WASHINGTON (Reuters) - The U.S. State Department on Friday urged the Baghdad government to avoid clashes in northern Iraq by limiting the movement of federal troops in disputed areas to those coordinated with the Kurdistan Regional Government. In a statement, it said Washington was concerned by reports of violent clashes around the town of Altun Kupri.  The reassertion of federal authority over disputed areas in no way changes their status   they remain disputed until their status is resolved in accordance with the Iraqi constitution,  it said. Iraqi forces on Friday took control of the last district in the oil-rich province of Kirkuk still in the hands of Kurdish Peshmerga fighters following a three-hour battle, security sources said. 