US President Barack Obama paid a four-hour surprise visit to Iraq on Tuesday, during which he told the US troops to make sure Iraq is stable before their withdrawal and said the Iraqis need to take responsibility for their own country.

US President Barack Obama visits Camp Victory in Baghdad, April 7, 2009. [Xinhua]

During his short visit to Iraq, his first since he took office three months ago, Obama met with Iraqi Prime Minister Nuri al-Maliki and inspected Camp Victory, the US military base on the outskirts of Baghdad.

He told his troops in the military base that the next 18 months of their mission in the war-torn country would be "critical", urging the troops to bear responsibilities to make sure Iraq is stable before the withdrawal.

In February, Obama announced a new strategy that will put an end to US combat operations in Iraq by August next year. Obama also pledged he would stick to a timetable for all American troops to be out of the country by the end of 2011.

Obama told some 600 cheering US troops at the base that the American forces had "performed brilliantly ... under enormous strain."

Meanwhile, he also called on Iraqis to take responsibility for the country of their own.

"It is time for us to transfer (control) to the Iraqis...They need to take responsibility for their country," Obama said.

Obama was received at the Baghdad airport by top US troops commander in Iraq Gen. Ray Odierno before immediately heading for Camp Victory. Obama discussed with him the planned draw down of troops and general elections due at the end of 2009.