U.S. Vice President Joe Biden said Wednesday the U.S. forces have begun a new mission in Iraq, a day after U.S. President Barack Obama announced the end of U.S. combat mission in the country.

"Operation Iraqi Freedom is over but the American engagement with Iraq will continue with the mission that begun today, Operation New Dawn," Biden told a ceremony at Camp Victory U.S. military base near Baghdad airport.

Biden and U.S. Defense Secretary Robert Gates are attending the ceremony at the base which includes the former presidential Saddam Hussein's Faw Palace near Baghdad airport.

The ceremony is to mark the end of U.S. combat mission and the start of the new "advise and assist" mission, dubbed "Operation New Dawn."

U.S. troops in Iraq had been reduced to below 50,000 soldiers. Washington said that the remaining U.S. troops will remain in Iraq to conduct support and training missions.