Foreign Minister Makiko Tanaka's reported criticism of a U.S. missile defense plan makes her planned visit to the U.S. unlikely, government sources said Tuesday.

While the Foreign Ministry has not received any response from the United States over Tanaka's desire to meet Secretary of State Colin Powell, negotiations are continuing over squeezing the meet into Powell's tight schedule.

Because the U.S. is unlikely to hold talks on weekends, and Tanaka will have difficulty getting away during the week due to her Diet schedule, it is increasingly unlikely that she will get to the U.S. before Prime Minister Junichiro Koizumi's visit June 30.