MINNEAPOLIS (AP) -- Delta, Continental, and United airlines say they're applying for permission to fly from the U.S. to Tokyo's Haneda Airport.

Delta and United are the biggest U.S. airlines serving Japan, and they already fly to Tokyo Narita airport. Continental is looking to expand its flights to Asia.

Flying to Haneda would put them in the airport closest to downtown Tokyo, which has mostly been used by domestic travelers. A proposed aviation treaty with Japan would open that airport to U.S. carriers for the first time since 1978.

Delta says it applied to the Transportation Department to fly to Haneda from Seattle, Detroit, Los Angeles, and Honolulu. United says it is wants to fly from Seattle. Continental's flights would be from the New York area and Guam.