The Clint Eastwood film"Letters from Iwo Jima" was named best film of 2006 by the National Board of Review on Wednesday in the first major award of the Oscar season.

Helen Mirren was named best actress for her portrayal of Britain's ruling Queen Elizabeth in"Queen Elizabeth," while Forest Whitaker won the best actor award for his role in"The Last King Of Scotland."

The awards were voted on by 120 film professionals who viewed more than 250 movies and can be an indicator of what to expect for the world's top film honors, the Academy Awards, held in February.

Eastwood's"Letters from Iwo Jima" -- the story of the battle of Iwo Jima between the United States and Imperial Japan during World War II -- is not due to be released in U.S. cinemas until December 20. It is the second Eastwood film to be released this year about the 1945 fight for the tiny Pacific island following"Flags of Our Fathers."