TORONTO -- "Room" star Jacob Tremblay returned Thursday to the star-packed film festival that launched his career, armed with a new tear-jerker drama and a handful of quips to charm a press conference.

The Vancouver nine-year-old fielded questions alongside co-stars of his newest film, "Burn Your Maps," which was making its world premiere at the Toronto International Film Festival.

Tremblay plays a young Chicago boy who believes he is actually a Mongolian goat herder.

He said it was a fun film to make, noting it was shot in the rolling foothills of the Canadian Rockies, where he ran through fields with goats and rode around on a horse.

"Goats are really cute, especially the baby ones. But they do smell a little bit," Tremblay quipped to a chuckling audience of journalists and festival staff.

"I also had to learn to ride a horse without a saddle. If you do that it kind of hurts, if you know what I'm saying."

Co-stars Vera Farmiga and Virginia Madsen had nothing but praise for the young star, who debuted last year in the captive thriller "Room" as a complete unknown.

In "Burn Your Maps," Tremblay takes centre stage as Wes, whose disturbing obsession with Mongolia extends to donning handmade traditional garb, devouring online Mongolian language lessons, and making his own herd of goats out of toilet paper.

The fantasy emerges after the family suffers a tragedy that sends each member reeling in their own way. Farmiga's fragile matriarch Alise questions the marital bonds with her husband, played by Marton Csokas.

Director Jordan Roberts said he first caught wind of Tremblay a year before shooting, when he saw a video of a "mesmerizing" six-year-old.

"There was no acting going on at all, he was 100 per cent present in this imaginary scenario and it just flabbergasted me," said Roberts, screenwriter for the Oscar-winning animated film "Big Hero 6."

It took a year to raise the money Roberts needed for the film, and when his first audition tape for the youngest role arrived, it was another video of Tremblay.

"And it was again mind-boggling," he said.

"He was a year or so older, incredibly mature. He made very powerful, strong choices. He has wonderful parents who obviously have something to do with what he does but when I saw his tape it was just staggeringly powerful again and completely honest."

The rest of the cast came together just as smoothly, Roberts said, although he set his eyes first on scoring Farmiga as a mother desperate to keep her crumbling marriage together.

Farmiga said it was easy to bond with Jacob for their mother-son scenes.

"He's a very savvy young actor. Very deep in touch with his emotions," said Farmiga.

"He has a very unique relationship with his own mom which I was able to witness on a daily basis and see how she is very much a part of his process. And I hung out with his mom a lot and have worked with his sister before so immediately there was a closeness."

Madsen said everyone on set made an effort to keep the workday fun and kid-friendly.

"To watch him running around with goats and just this wonderful human having a great time being a kid (was great)," she said.

"And it's not always like that for young people on movies but Jordan and I think all of us embraced this environment and he just got to be free."

Roberts said Mongolia didn't have the infrastructure to allow the film to be shot in the east Asian country. He was pleasantly surprised to find remarkable geographical similarities in Kananaskis, Alta.

And when he learned that roughly 700 Mongolians live in Calgary -- allowing him to cast real Mongolians in the film -- he was sold.

Roberts stayed in Canada for post-production, spending five months in Toronto where he held several focus groups.

"This film was made in Canada and Canada helped me make this film. It really genuinely did," Roberts said.

"I don't have to tell anyone that my country is engaged in a kind of ugliness that is unprecedented and I found the gentleness and the kindness and the humanity of the people who came in early in this city, people I met -- waiters, bartenders, people I met -- they came and they watched the early cuts of the film, they were the people I talked to and their humanity encouraged me to continue down the path I was on."

The Toronto International Film Festival wraps Sunday.