Vice President Joe Biden has arrived in Baghdad to preside over a ceremony marking the formal end to U.S. combat operations in Iraq.
Wednesday's ceremony signals a shift toward a greater U.S. diplomatic role as the military mission dwindles seven years after the American invasion that toppled Saddam Hussein.
Biden also plans to push for Iraqi leaders to end their political stalemate and form a new government. Parliamentary elections nearly six months ago left Iraq without a clear winner.
The Obama administration had set an Aug. 31 deadline for cutting back U.S. troop numbers to 50,000 from a high of 170,000 at the height of the war in 2007. All U.S. troops are to leave Iraq by the end of 2011.