MEXICO CITY President Manuel Zelaya of Honduras was ousted by the army on Sunday, capping months of tensions over his efforts to lift presidential term limits.
In the first military coup in Central America since the end of the cold war, soldiers stormed the presidential palace in the capital, Tegucigalpa, early in the morning, disarming the presidential guard, waking Mr. Zelaya and putting him on a plane to Costa Rica.
Mr. Zelaya, a leftist aligned with President Hugo Chávez of Venezuela, angrily denounced the coup as illegal. “I am the president of Honduras,” he insisted at the airport in San José, Costa Rica, still wearing his pajamas.
Later Sunday the Honduran Congress voted him out of office, replacing him with the president of Congress, Roberto Micheletti.
The military offered no public explanation for its actions, but the Supreme Court issued a statement saying that the military had acted to defend the law against “those who had publicly spoken out and acted against the Constitution’s provisions.”
Leaders across the hemisphere, however, denounced the coup, which American officials on Sunday said they had been working for several days to avert.
President Obama said he was deeply concerned and in a statement called on Honduran officials “to respect democratic norms, the rule of law and the tenets of the Inter-American Democratic charter.
“Any existing tensions and disputes must be resolved peacefully through dialogue free from any outside interference,” he said. His quick condemnation offered a sharp contrast with the actions of the Bush administration, which in 2002 offered a rapid, tacit endorsement of a short-lived coup against Mr. Chávez.
The Organization of American States issued a statement calling for Mr. Zelaya’s return and said it would not recognize any other government. The organization’s secretary general, José Miguel Insulza, called an emergency meeting of the group to weigh further actions.
The arrest of Mr. Zelaya was the culmination of a battle that had been simmering for weeks over a referendum, which was to have taken place Sunday, that he hoped would lead to a revision of the Constitution. Critics said it was part of an illegal attempt by Mr. Zelaya to defy the Constitution’s limit of a single four-year term for the president.
Early this month, the Supreme Court agreed, declaring the referendum unconstitutional, and Congress followed suit last week. In the last few weeks, supporters and opponents of the president have held competing demonstrations. On Thursday, Mr. Zelaya led a group of protesters to an Air Force base and seized the ballots, which the prosecutor’s office and the electoral tribunal had ordered confiscated.
When the army refused to help organize the vote, he fired the armed forces commander, Gen. Romeo Vásquez. The Supreme Court ruled the firing illegal and reinstated General Vásquez.
As the crisis escalated, American officials began in the last few days to talk with Honduran government and military officials in an effort to head off a possible coup. A senior administration official, who briefed reporters on the condition of anonymity, said the military broke off those discussions on Sunday.
The two nations have long had a close military relationship, with an American military task force stationed at a Honduran air base about 50 miles northwest of Tegucigalpa. The unit focuses on training Honduran military forces, counternarcotics operations, search and rescue, and disaster relief missions throughout Central America.
In Costa Rica, Mr. Zelaya told the Venezuelan channel Telesur that he had been awoken by gunshots. Masked soldiers took his cellphone, shoved him into a van and took him to an air force base, where he was put on a plane. He said he did not know that he was being taken to Costa Rica until he landed at the airport in San José.
“They are creating a monster they will not be able to contain,” he told a local television station in San José. “A usurper government, that emerges by force, cannot be accepted, will not be accepted by any country.”