Prime Minister Junichiro Koizumi has pledged maximum support to the United States if it retaliates against the organizers of Tuesday's terrorist attacks in New York and Washington, but ruled out Japan joining a possible multinational force against them.

Speaking at the Foreign Correspondents' Club of Japan on Friday, Koizumi said Japan's support for the U.S. will be constrained by the limitations imposed by its pacifist Constitution.

When asked if Japan would consider joining a possible multinational force against those responsible for the terrorist attacks, Koizumi said, "The same discussion erupted during the Persian Gulf War.