BAGHDAD (Reuters) -- Britain will begin withdrawing its remaining 4,000 combat troops from Iraq at the end of March, six years after helping to topple Saddam Hussein as Washington's main ally in the U.S.-led invasion.
The withdrawal of combat troops stationed in the southern city of Al-Basrah is due to be completed by the end of July. A residual presence of a few hundred personnel will stay on to train Iraqi police, a British military spokesman in Al-Basrah said.
The 2003 invasion unleashed widespread sectarian killing, and the war in Iraq has proven both costly and unpopular for the United States and Britain. Violence has since dropped sharply in the past year, and foreign troops are preparing to leave.
U.S. President Barack Obama said last month that the United States will withdraw around 100,000 troops from Iraq by the end of August 2010, leaving a force of up to about 50,000.
"The gradual drawdown will start from March 31. We will cease operations around May 31.... All the combat forces, about 4,000 troops, must be out of Iraq by the end of July," British military spokesman Lieutenant Colonel Dickie Winchester said.
The U.S. military will send some 900 military police to Al-Basrah to lead police training, part of U.S. plans to open a headquarters there to command its forces in southern Iraq, Winchester said.
Iraqi forces are responsible for security in the south.
"A U.S. headquarters will be established here. The U.S. headquarters will take command of the south of Iraq," he said, speaking by telephone from Al-Basrah.
Britain sent 46,000 troops to the Persian Gulf for the 2003 invasion. British troops once controlled the southern oil-rich province of Al-Basrah, but withdrew to Al-Basrah airport in 2007, leaving Iraqi forces to take control of security.
Basra was once overrun by gangs and militias vying for its oil wealth, but is now relatively calm after Iraqi Prime Minister Nuri al-Maliki ordered a security crackdown last year.
Iraqi forces sent to restore order found themselves shooting at gunmen in police uniform, and the British military has said restoring confidence in Al-Basrah's police is key to stability.
"The Iraqi Army is ready [and] capable of securing Basra.... The police will still continue to be trained," Winchester said.