Prime Minister Naoto Kan stressed Thursday the importance of the Japan-U.S. alliance and the importance of the continued presence of American forces in Okinawa for the national security.

Kan apologized to Okinawa locals for "causing confusion and deeply hurting their feelings" over the contentious relocation of U.S. Marine Corps Air Station Futenma during a speech hosted by the Friendship Exchange Council, a nonprofit international exchange organization.

The prime minister, however, noted that the U.S. military presence was necessary amid the "extremely grave" situation in Asia at present due in large part to North Korea's nuclear threat.