The United States has sounded out Japan on the possibility of the Self-Defense Forces providing logistic support if the U.S. launches a military reprisal in the wake of the Sept. 11 terrorist attacks, diplomatic sources said Monday.

Naval transport has been cited as one role the SDF could play in the event of a U.S. response to the attacks on the World Trade Center and the Pentagon.

The sources said Richard Armitage, U.S. deputy secretary of state, made the inquiry Saturday through Shunji Yanai, Japan's ambassador in Washington.

Armitage met Yanai to discuss the matter but neither Japanese or American officials would comment on the meeting, apparently out of concern that the U.S. request would be perceived in Japan as U.S. pressure.