Academy Award-winning star of Irish/Canadian co-production Room, Brie Larson, has penned a heartfelt note to her co-star Jacob Tremblay as they celebrate the end of the press tour for the movie.

Taking to Instagram, Larson posted an image of her sharing a toast with her on-screen son Tremblay, along with a touching message about their time spent together on set, their friendship and the effect Room has had on her.

"28 weeks ago (according to Instagram) Room premiered at the Telluride Film Festival. After the screening Jacob Tremblay and I toasted. He had chocolate milk and I had red wine," she said. "I remember feeling so vulnerable after sharing this movie with the world for the first time; unsure of what was to come.

"Last night marked what may be our final toast to this film. He had a soda and I had sake. We are in Japan. Together we have travelled the globe, spent almost two years hanging out, playfully arguing about things like who can hold their breath the longer and talking at length about Room."

Larson continued, "At its core, every step of the way has been taken with love. We were generous and patient with each other. We laughed a lot, especially when it was hard. We picked each other up, answered for the other when one was tired and always kept silliness alive.

"Thank you Room for bringing us together. Thank you Room for uniting us with the rest of the world. Thank you to everyone who shared this journey with us. I will never ever forget it."