Japan's defense chief signalled on Sunday that the country's troops could extend their humanitarian mission to Iraq beyond an initial Dec. 14 deadline, possibly for another year. Yoshinori Ohno comments on NHK public television came amid a raging debate over whether Japan should withdraw its troops from Samawa in southern Iraq. Newspaper polls have shown that more than half the electorate opposes an extension. "Reconstruction is still under way, so we must continue the support," NHK quoted Ohno as saying. "As for making an exit, reconstruction in Iraq must be to some extent complete," Ohno said. "One possible opportunity would be December next year, which is the end of the mandate for multinational forces in Iraq," he added, referring to a UN Security Council mandate. Japan has about 550 troops in Samawa, taking part in their most dangerous overseas deployment since World War Two. A pacifist constitution limits their activities to aid and reconstruction, including providing fresh water. No official announcement has been made on when they will come home, but Prime Minister Junichiro Koizumi, a close ally of U.S. President George W. Bush, is widely expected to keep the troops in Samawa beyond December. On the assumption the extension will go ahead, Japan has asked the British army to help protect its troops after Dutch soldiers withdraw from the area in March next year, a Japanese newspaper said on Sunday.