The United States will keep a military base in Bosnia after NATO hands over its peacekeeping mission to the European Union in December, U.S. Ambassador Douglas McElhaney said on Friday. Washington has also accepted Bosnia's offer to send a de-mining unit to Iraq in support of the U.S.-led coalition, McElhaney said, adding there had been "substantial progress in preparations". "The U.S. has accepted Bosnia's generous offer of continued use of the Tuzla base after SFOR completes its mission," he said, referring to the main U.S. base in Bosnia, which currently forms part of the NATO-led Stabilisation Force (SFOR). McElhaney declined to give details on the size and the mandate of the future U.S. base. About 900 U.S. soldiers are now deployed in the country as part of SFOR, most of them at the Orao base near the northern town of Tuzla. They had been expected to leave by Dec. 2, when NATO hands over the nine-year-old mission to a 7,000-strong EU force, EUFOR. But an SFOR spokesman said some of them would now stay. --More 2048 Local Time 1748 GMT