Actress Maggie Gyllenhaal has sparked controversy after declaring her native America "is responsible in some way" for the September 11 attacks in New York and Washington DC.

The 27-year-old Mona Lisa Smile star made the comments in an interview last week, provoking a strong reaction from her patriotic countrymen.

In a statement issued by her publicist, Gyllenhaal says: "(September 11 was) an occasion to be brave enough to ask some serious questions about America's role in the world. Because it is always useful as individuals or nations to ask how we may have knowingly or unknowingly contributed to this conflict.

"Not to have the courage to ask these questions of ourselves is to betray the victims of 9/11."