WASHINGTON — The U.S. has expressed strong concern over the confusion surrounding reports that Foreign Minister Makiko Tanaka has raised doubts about missile defense and the Japan-U.S. alliance, the Japanese ambassador to the U.S. said Tuesday.

"The U.S. wonders what is unfolding in Japan," Shunji Yanai told reporters. He said the U.S. government is contacting those countries whose foreign ministers have met recently with Tanaka to verify her statements.

Tanaka has hit the headlines in Japan during the past week over reports that she questioned the missile defense plans of U.S. President George W. Bush in separate meetings with her Australian, Italian and German counterparts.