DAMASCUS, Syria — Syria on Sunday derided President Barack Obama's decision to hold off on punitive military strikes, but also took precautions by reportedly moving some troops and military equipment to civilian areas.

The Obama administration countered that its case for military action against the regime of Syrian President Bashar Assad is getting stronger, saying it now has evidence that the toxic gas allegedly used in strikes on rebel-held areas was the nerve agent sarin.

The administration predicted Sunday it will obtain congressional backing for limited strikes. After days of edging closer to military action against Syria, Obama suddenly announced Saturday he would first seek approval from Congress, which gets back from summer break Sept. 9.

Assad, in turn, tried to project confidence in his escalating showdown with the U.S., saying in comments carried by state media Sunday that Syria is "capable of confronting any external aggression."

From the sidelines, others exhorted the U.S. either to get involved or stay out of the brutal two-and-a-half-year-old conflict that has claimed more than 100,000 lives and displaced millions of people.

The Arab League at an emergency meeting in Cairo Sunday called on the United Nations and the international community to take "deterrent" measures under international law to stop the Syrian regime's crimes, but could not agree on whether to back U.S. military action.

Arab foreign ministers at the meeting in their closing statement held the Assad regime responsible for the "heinous" chemical attack, saying the perpetrators should be tried before an international court "like other war criminals."

At the Vatican, Pope Francis said he would stage a worldwide prayer vigil for Syria on Sept. 7 and called on all sides to lay down their arms.

"My heart is deeply wounded by what is happening in Syria and anguished by the dramatic developments" on the horizon, Francis told crowds in St. Peter's Square, forgoing the usual religious theme of his weekly address.

The main Syrian political opposition, which operates largely from exile, warned that Obama would give dictators in Iran, North Korea and elsewhere a free pass to commit atrocities if he does not punish Assad.

In the Syrian capital Damascus, some said the reprieve from Washington was only prolonging their torment.

A 29-year-old city resident said he reinforced his window with tape in anticipation of an imminent attack.

"I know people who prepared sleeping pills to give to their kids the night of the attack so they can sleep and not be scared," said the man, who only gave his first name, Nasib, for fear of reprisals.

Nearly two weeks after the alleged chemical weapons attacks on areas east and west of Damascus, many unanswered questions remain.

Neither the U.S. nor the Syrian regime, which blames rebels for the attacks, has publicly presented proof.

Syria's deputy foreign minister, Faysal Mikdad, claimed Sunday that Obama stepped back from his threat to attack because he lacks evidence of Syrian government involvement in the Aug. 21 attacks.

"The hesitation and the disappointment is so obvious in the words of President Obama yesterday," Mikdad told reporters in Damascus. "The confusion was clear as well."

In a sharply worded front-page article, the state-run newspaper Al-Thawra, expressing official thinking, said Obama's turn-about on military action was "the start of the historic American retreat."

Yet despite the official hubris, there were signs the regime was taking precautions.

The main Western-backed opposition group, the Syrian National Coalition, said the army moved troops as well as rocket launchers, artillery and other heavy weapons inside residential neighborhoods in cities nationwide. The coalition said Assad ordered detainees to be moved to military targets for use as human shields against U.S. strikes.

Three Damascus residents, speaking on condition of anonymity for fear of reprisals, confirmed such movements.

One man said two members of the elite Republican Guards broke into an empty house he owns, showing him an official paper stating they were authorized to do so because Syria is at war. He said he bribed the soldiers and they left. A woman in another area said soldiers moved into a school next to her house and she was terrified.

In Washington, U.S. Secretary of State John Kerry tried to sharpen the arguments for military action Sunday in a serious of appearances on television news shows.

Kerry said he expected American lawmakers to recognize that the "credibility of the United States is on the line."

He said Obama has the authority to launch retaliatory strikes with or without Congress' approval, but Kerry stopped short of saying the president would do so if the House or Senate withholds support.

"The stakes are just really too high here," Kerry said. "We are not going to lose this vote."

A White House draft resolution asks Congress to authorize force to "deter, disrupt, prevent and degrade" the Assad regime's ability to use chemical weapons. It doesn't lay out a timeline for action.

Kerry also said the United States has received hair and blood samples from first responders indicating that Syria's government forces used sarin in the Aug. 21 attacks. It was the first piece of specific physiological evidence cited by the administration.

Previously, the U.S. only said regime troops fired rockets carrying an unnamed nerve agent at the Damascus suburbs, killing at least 1,429 civilians, including more than 400 children.

The Syrian Observatory for Human Rights, a Britain-based group that collects information from a network of anti-regime activists in Syria, has said it has only been able to confirm the names of 502 dead. It has challenged the U.S. to release the information that led to the higher toll.

Obama has said that in making his final decision, he will not wait for findings by U.N. chemical weapons experts who collected biological and soil samples in the stricken areas near Damascus last week.

U.N. chief Ban Ki-moon asked the head of the team on Sunday to expedite the testing of the samples and report back to him as soon as possible, U.N. spokesman Martin Nesirky said.

The samples will be sent Monday to laboratories around Europe, he said, adding that he could not say when the results will be in.

Ban has said no action should be taken before the U.N. team has presented its findings. However, U.S. officials have argued that there is no doubt chemical weapons were used, and that it's not part of the U.N. inspectors' mandate to determine who fired them.

In Cairo, at an emergency sesson of the 22-member Arab League, the Saudi Arabian foreign minister, Saud al-Faisal, prodded member states to back international measures against the Syrian regime to "deter this aggression by all possible means."

If the world does nothing, the Syrian regime will be encouraged to "go on with its crimes," he said.

Syrian Opposition Coalition President Ahmed Assi al-Jarba urged the Arab countries to support an "international operation to stop the killing and destruction machine" of the Assad regime. The opposition coalition has represented Syria at Arab League meetings since the Assad government's membership was suspended earlier this year.

However, key members such as Egypt and Iraq opposed sanctioning any military action against Syria, which resulted in the final statement being watered down.

In Israel, Prime Minister Benjamin Netanyahu said his country is ready for "any possible scenario," a reference to fears of Syrian reprisals against Israel in the event of a U.S. strike on the Assad regime.

Netanyahu did not address Obama's latest decisions, but media commentators and hard-line politicians said the U.S. president appeared indecisive.

___

Laub reported from Beirut. Associated Press writers Yasmine Saker and Ryan Lucas in Beirut, Maria Sanminiatelli at the United Nations, Sara El Deeb in Cairo and Frances D'Emilio in Rome contributed to this report.

Also on HuffPost:

Captions courtesy Reuters.
Loading Slideshow...
  • April 29, 2011

    United States slaps sanctions on Syria's intelligence agency and two relatives of President Bashar al-Assad, in Washington's first concrete steps in response to a crackdown on anti-government protests inspired by the "Arab Spring." <em>Pro-Syrian regime protesters gather during a protest against sanctions, in Damascus, Syria, on Friday Dec. 2, 2011. (AP Photo/Bassem Tellawi)</em>

  • Aug. 18, 2011

    For the first time, Obama calls for Assad to step down, saying: "For the sake of the Syrian people, the time has come for President Assad to step aside." Britain, France and Germany also call for Assad to go. <em>U.S. President Barack Obama leaves the Oval Office as he walks to Marine One prior to departing from the South Lawn of the White House in Washington, DC, on August 18, 2011. Obama led a chorus of calls by world leaders for Syria's president to step down, as the United Nations warned his regime could be guilty of crimes against humanity. (SAUL LOEB/AFP/Getty Images)</em>

  • July 19, 2012

    U.S. Ambassador to the United Nations Susan Rice calls the Russian and Chinese vetoes of a U.N. Security Council resolution on Syria "dangerous and deplorable." <em>Syria's UN Ambassador Bashar Ja'afari, left, thanks a member of the Chinese UN delegation as China's UN Ambassador Li Baodong, second from right, and Russia's UN Ambassador Vitaly Churkin look on, after a Security Council meeting on the situation in Syria at the United Nations in New York, Thursday, July 19, 2012. Russia and China vetoed a United Nations resolution to impose non-military sanctions on Syria. (AP Photo/Kathy Willens)</em>

  • July 23, 2012

    Obama says Assad will be held accountable if he makes the "tragic mistake" of using Syria's stockpile of chemical weapons. <em>This citizen journalism image provided by Shaam News Network SNN, taken on Tuesday, July 24, 2012, shows bodies of Syrians killed during their funeral procession in the suburb of Daraya, Damascus, Syria. (AP Photo/Shaam News Network, SNN)</em>

  • July 23, 2012

    Syria says it could use chemical weapons in response to any "external aggression" but they will not be used in Assad's campaign to crush the uprising in what appeared to be the first time that Syria acknowledges it might possess non-conventional weapons. <em>In this June 3, 2012 file photo released by the Syrian official news agency SANA, Syrian President Bashar Assad delivers a speech at the parliament in Damascus, Syria. (AP Photo/SANA, File)</em>

  • Aug. 20, 2012

    Obama warns Assad that the use or deployment of chemical or biological weapons in his country's conflict would be a "red line" for the United States. "A red line for us is (if) we see a whole bunch of chemical weapons moving around, or being utilized. That would change my calculus," he tells reporters. <em>U.S. President Barack Obama speaks during a press conference in the Briefing Room of the White House Aug. 20, 2012 in Washington, D.C. (BRENDAN SMIALOWSKI/AFP/Getty Images)</em>

  • Dec. 3, 2012

    Obama warns Assad "the world is watching" and there would be consequences if he uses chemical weapons against Syrian opposition forces. "The use of chemical weapons is and would be totally unacceptable and if you make the tragic mistake of using these weapons, there will be consequences and you will be held accountable," he says in a speech to a gathering of biological, chemical and nuclear weapons proliferation experts. <em>U.S. President Barack Obama greets members of the military and military community after speaking during the Nunn-Lugar Cooperative Threat Reduction (CTR) symposium at the National Defense University in Washington on December 3, 2012. Obama directly warned Syria's President Bashar al-Assad that he would face 'consequences' if he made the 'tragic mistake' of turning chemical weapons on his own people. (SAUL LOEB/AFP/Getty Images)</em>

  • March 19, 2013

    Syria's government and rebels accuse each other of launching a deadly chemical attack near the northern city of Aleppo in what would be the first use of such weapons in the two-year conflict. <em>In this Tuesday March 19, 2013 file photo released by the Syrian official news agency SANA, a Syrian victim who suffered an alleged chemical attack at Khan al-Assal village according to SANA, receives treatment by doctors, at a hospital in Aleppo, Syria. (AP Photo/SANA, File)</em>

  • April 26, 2013

    Obama warns Assad that any use of chemical weapons in Syria's civil war would be a "game changer" but remains cautious about endorsing intelligence assessments that such weapons had been deployed. <em>This citizen journalism image taken on Thursday, April 25, 2013 and provided by Edlib News Network, ENN, which has been authenticated based on its contents and other AP reporting, shows a wounded Syrian man holding his injured son after an air raid on the northwestern town of Saraqeb in the province of Idlib, Syria. (AP Photo/Edlib News Network ENN)</em>

  • June 8, 2013

    Syrian government troops backed by guerrillas from Lebanon's Hezbollah seize the western village of Buwayda to end rebel resistance around the strategically important town of Qusair in a success for Assad forces. The involvement of Iran-sponsored Hezbollah and gains by Syrian forces prompt renewed U.S. debate on arming Assad's opponents. <em>In this citizen journalism image provided by Edlib News Network, ENN, anti-Syrian regime protesters hold a placard with a caricature on it against Hezbollah leader Sheik Hassan Nasrallah, top left, Iran's Supreme Leader Ayatollah Ali Khamenei, top right, and U.S. President Barack Obama, below, during a demonstration at Kafr Nabil town in Idlib province, northern Syria, Friday, June 7, 2013. (AP Photo/Edlib News Network ENN)</em>

  • June 13, 2013

    After two months of caution about reports Syria used chemical weapons, the White House says U.S. intelligence agencies have concluded that Assad's forces indeed used such weapons, including the nerve agent sarin, on a small scale against the opposition multiple times, killing 100 to 150 people. The White House vows to increase military aid to the Syrian rebels. <em>U.S. President Barack Obama departs the White House on June 16, 2013. Obama heads to Belfast for the G8 summit where he will meet Russia's Vladimir Putin on June 17 for potentially vexatious talks, as both leaders now offer open military backing to rival sides in Syria's civil war. (NICHOLAS KAMM/AFP/Getty Images)</em>

  • Aug. 21, 2013

    Syria's opposition accuses government forces of gassing hundreds of people by firing rockets that released deadly fumes over rebel-held neighborhoods near Damascus, killing men, women and children as they slept. If confirmed, it would be the worst chemical weapons attack in 25 years. <em>This Aug. 21, 2013, file citizen journalism image provided by the Local Committee of Arbeen which has been authenticated based on its contents and other AP reporting, shows Syrian citizens receiving treatment after an alleged poisonous gas attack fired by regime forces, according to activists in Arbeen town, Damascus, Syria. (AP Photo/Local Committee of Arbeen, File)</em>

  • Aug. 26, 2013

    Secretary of State John Kerry says all nations must stand up for accountability on the "undeniable" use of chemical weapons in Syria, where he said the government maintained custody of such weapons. "Let me be clear: The indiscriminate slaughter of civilians, the killing of women and children and innocent bystanders by chemical weapons is a moral obscenity." <em>An image grab taken from a video uploaded on YouTube by the Local Committee of Arbeen on Aug. 21, 2013 allegedly shows Syrians covering a mass grave containing bodies of victims that Syrian rebels claim were killed in a toxic gas attack by pro-government forces in eastern Ghouta and Zamalka, on the outskirts of Damascus. DSK/AFP/Getty Images)</em>

  • Aug. 30, 2013

    In separate statements, Obama and Kerry harshly condemn the Syrian government, saying the Aug 21. attack cannot go unpunished. Obama says: "We cannot accept a world where women and children and innocent civilians are gassed on a terrible scale," while Kerry calls Assad "a thug and a murderer." But they say any military response by the United States would be measured to avoid open-ended commitments. <em>U.S. Secretary of State John Kerry speaks about the situation in Syria from the Treaty Room at the State Department in Washington, DC on August 30, 2013. (SAUL LOEB/AFP/Getty Images)</em>

  • Aug. 30, 2013

    U.S. intelligence agencies publicly disclose some of the information that led to a "high-confidence" assessment that the government of Assad carried out a chemical weapons attack on neighborhoods outside Damascus, causing the deaths of an estimated 1,429 Syrians on Aug. 21. <em>In this August 1, 2013, file photo, posted on the official Facebook page of the Syrian Presidency, purports to show Syrian President Bashar Assad talking with soldiers with during Syrian Arab Army day in Darya, Syria. (AP Photo/Syrian Presidency via Facebook, File)</em>

  • Aug. 31, 2013

    Obama says he had authorized the use of military force to punish Syria, with military assets to carry out a strike in place and ready to move on his order, but he would first seek authorization from Congress. "Today I'm asking Congress to send a message to the world that we are ready to move as one nation," he said. <em>U.S. President Barack Obama speaks about Syria from the Rose Garden at the White House in Washington, DC, on August 31, 2013, with Vice President Joe Biden. Obama said Saturday he will ask the U.S. Congress to authorize military action against Syria, lifting the threat of immediate strikes on President Bashar al-Assad's regime. (JIM WATSON/AFP/Getty Images)</em>