US President Barack Obama has welcomed some of the last returning soldiers from Iraq at the Andrews Air Force base in the US capital, following the final pullout over the weekend.

U.S. President Barack Obama (L) greets troops during a ceremony to mark the return of the United States Forces-Iraq Colors and the end of the Iraq war on December 20, 2011 at Joint Base Andrews, Maryland.

President Obama and Vice President Joe Biden observed the end of the war in Iraq in solemn military tradition, marking the official return of the US Forces' Iraq flag.

Tuesday's ceremony at the military post in suburban Washington marks the conclusion of the nine-year conflict.

President Barack Obama greets troops as they step off a plane on the tarmac at Andrews Air Force Base, Md., Tuesday, Dec. 20, 2011, during a ceremony marking the return of the United States Forces-Iraq Colors and the end of the war in Iraq.

Obama and Biden welcomed home Gen. Lloyd Austin, the top US. commander in Iraq, and watched the flag's arrival.