Baghdad: US President Barack Obama will withdraw forces from Iraq sooner than the three-year deadline agreed by ex-president George W. Bush, Iraqi Prime Minister Nouri Al Maliki said on Monday.

Under a pact agreed with the previous US administration, the US troops that invaded Iraq in 2003 to topple Saddam Hussein have until the end of 2011 to leave.

But Obama pledged during his election campaign to pull out combat troops within 16 months. US defense officials say that 16-month timeline is one of the options on the drawing board.

The pace of withdrawals "will be accelerated and occur before the date set in the agreement," Maliki told a crowd of supporters in the southern Iraqi city of Babel during a campaign rally ahead of January 31 provincial elections.

"As a result, we must boost the determination of our brothers in the ministries of defense and interior to complete the building up of our military and security forces to take on fully the task of providing and preserving growing security."