McGregor, along with actress Naomi Watts, star in the upcoming film "The Impossible." The movie is based on the true story of a vacationing family who get separated from each other after a tsunami hits their resort (the 2004 Indian Ocean Tsunami).
"When you make a true story, you have a responsibility to the people that you're playing. But in this film you have a responsibility to everybody that was touched by the tsunami," says McGregor, in a new TV spot.
"She's an incredibly strong, courageous woman. She is an inspiration," adds Watts, regarding her real-life counterpart, Maria, who she plays in the film.
You can watch the newest TV spot for "The Impossible" above. The film hits theaters on December 21.