WASHINGTON (Reuters) - President Barack Obama has chosen retired Marine Corps General John Allen, who served as the top U.S. commander in Afghanistan, to coordinate international efforts to fight Islamic State militants in Iraq and Syria, a U.S. official said on Friday.

Allen has long experience working with leaders in the region, both as a commander in Iraq and as deputy head of U.S. Central Command, which controls U.S. forces in the region.

The official said he would be named as the Special Presidential Envoy for the Global Coalition against ISIL, the acronym the administration used for the Sunni Islamist movement.

Allen was deployed in Iraq between 2006 and 2008, where he served as commanding general of the 2nd Marine Expeditionary Brigade. He served in Anbar Province and helped nourish the Sunni Awakening, which reduced violence in that part of the country and defeat al Qaeda in Iraq and other insurgents.

After leaving Iraq he was deputy commander of Central Command and went on to serve as head of U.S. and international forces in Afghanistan from July 2011 until February 2013.

He was commander in Afghanistan during the height of the U.S. military surge against the Taliban, which helped reduce the level of militant violence as the United States prepared to hand over the lead combat role to Afghan forces.

Since leaving the military in 2013, Allen has worked as an adviser to Secretary of State John Kerry and Defense Secretary Chuck Hagel. He has also been a special U.S. envoy on security issues in talks between Israel and the Palestinians.

(Reporting by David Alexander; Editing by David Storey and James Dalgleish)