Ichiro Ozawa, president of the Democratic Party of Japan, said Wednesday the Self-Defense Forces' participation in NATO's International Security Assistance Force in Afghanistan would not violate the Constitution, contrary to the claims of the Liberal Democratic Party-New Komeito ruling coalition, which has rejected his proposal.

During a news conference, Ozawa pointed out that Japan is a signatory of the U.N. and activities authorized by that body, including the ISAF, should not, therefore, be viewed as unconstitutional.

"Japan became a member (of the U.N.), promising to answer to its every possible demand, to give its full cooperation," Ozawa said. If joining the ISAF activities is unconstitutional, "that would make (Japan) a liar. That would mean that Japan's Constitution and the U.N. Charter are inconsistent."