TOKYO - Hundreds of demonstrators marched through central Tokyo on Sunday, calling for the withdrawal of Japanese troops from Iraq three years after the start of the U.S.-led war in Iraq.

The demonstration, the second in two days, came as the Japanese government puzzles over when to bring home its 600 or so noncombat troops, who have been engaged in reconstruction activities in the southern town of Samawa since January 2004.

"Bring the troops back from Iraq," read banners carried by some of the Tokyo demonstrators, who chanted and played drums as they marched.

"It has been three years since the war started and the American troops are still there, as well as the Japanese," said 43-year-old office worker Kumiko Shimizu. "I just want to put a stop to it as soon as possible."

Foreign Minister Taro Aso said on Saturday the government was putting off the decision, the Nihon Keizai Shimbun reported.

"The Iraqis have not formed a new administration, so there is no logic to withdrawing the troops now," Aso told reporters in Sydney, the paper said.

Aso was in Australia for meetings with U.S. Secretary of State Condoleezza Rice and Australian Foreign Minister Alexander Downer.

"The situation does not permit a decision on when to end our mission," the Nikkei quoted Aso as telling Downer.

Earlier media reports had said the government wanted to withdraw the troops, whose activities are strictly limited by the country's pacifist constitution, by the end of May, but could come under pressure from the United States to stay longer.

Opinion polls have shown that the majority of the Japanese electorate wants the troops brought home from their most dangerous overseas mission since World War Two in the first half of this year.