Washington has informally asked Japan to extend the mission of Japanese troops in Iraq beyond the current December deadline, Tokyo government sources said Friday.

The move is based on a request from the interim Iraqi government that the U.S.-led multinational forces stay in the country beyond next year, the sources said.

Japan is currently withholding a reply, but one senior Foreign Ministry official said another extension of the Self-Defense Forces deployment would be inevitable if the multinational forces are to stay.