'He's an irreplaceable person': Zoe Saldana pays tribute to late Star Trek co-star Anton Yelchin during appearance on The Late Show

Zoe Saldana paid a moving tribute on Monday to her Star Trek co-star Anton Yelchin who tragically died last month in a freak accident.

While promoting Star Trek Beyond on The Late Late Show With Stephen Colbert, the 38-year-old actress spoke of the 'terrible loss' of the 27-year-old actor who died when his car crushed him outside his home.

She also insisted that the stars of the sci-fi movie, along with director Justin Lin and producer J.J. Abrams, were making an extra effort to promote the movie in the late star's honor.

In mourning: Zoe Saldana during a chat show appearance on Monday said the Star Trek cast and crew were still in mourning over the death of actor Anton Yelchin 

'He had just turned 18 when we met him and he was the youngest one of the crew and I almost feel like he was the wisest one,' Zoe insisted of her co-star who was part of the cast since the 2009 franchise reboot.

'So it was a terrible loss. We're mourning - he's an irreplaceable person and the kindest person. And he loved what he did.'

The actress - in a black dress with red shoes - insisted: 'So I'm here today - and the rest of the cast and J.J. and Justin - we're here promoting the movie mainly for him because he would have loved that.'

Tragic death: Anton, shown in April in Hollywood, died last month in a freak accident at his home

Zoe - who revealed that she is set to film four more Avatar movies - admitted that while she was a sci-fi fan growing up it was 'not of Star Trek.'

'But I always knew that it was something big,' she insisted as Colbert teased her, claiming they would cut out her admission from the final broadcast.

She did, however, insist that she believes the series may have been pivotal in inspiring people that anything is possible - and may even have helped shape the political landscape.

Sci-fi fans: Stephen Colbert and Zoe talked about their mutual like of science fiction

'Barack Obama mentioned being a fan of the show - maybe this was one of those shows that really inspired him to believe that he could actually be president of the Unites States of America,' she insisted, with Colbert joking that he genuinely believes the president is 'part Vulcan' because he is 'very logical, very cool demeanour.'

Zoe added: 'I do believe that art has the ability to inspire and inflict hope on people and I like taking on that responsibility and being a part of good work.'

The host also teased her when she said she is a pro at handling her 20-month-old twin boys to people when she meets them, with Colbert asking: 'So you hand your baby to strangers sometimes?'

Keeping dry: The Star Trek star wore a long-sleeved black dress and red heels to the taping

Sci-fi films: Zoe also has four Avatar films that she's set to star in

'Did I mention I have 20-month-old twin identical boys?' she smiled in response, saying she only gets by thanks to 'caffeine and a husband who I just boss around.'

The show was being taped live to bring updates from the Republican National Convention, with Zoe admitting of the election: 'This is the first time as an American that I'm looking out and thinking. ''I'm a little worried''.'

'Whoever wins, there's still a good chance that this time next year there will still be a United States of America,' Colbert replied. 'That's fairly certain.'

Little worried: The actress admitted she was a little worried about the country this political season

He had opened the show wearing a boating hat and Stars and Stripes waistcoat as he sang a number about how they were about to 'witness history as the RNC crowns their orange manatee.'

Other lyrics joked about how there would be 'entire airplane hangar filled with Donald Trump's ex-wives' as well as 'maybe members of the clan' - but 'no Muslims or Latinos because I think they've all been banned.'

Jon Stewart joined him for a skit about Trump's unexpected success, and then showed footage of the candidate as he walked out at the convention to Queen's rock classic We Are The Champions.

'Yes, we are the champions of the world and we are going to restore conservative American values by entering to the music of a bisexual Englishman,' Colbert joked.

He's back: Jon Stewart made a guest appearance on the chat show

Him too: The chat show host also revived his character from the Colbert Report