Three hundred US Marines have been deployed to northern Jordan to pave the way for the West to arm Syrian rebels.

A Patriot anti-aircraft missile system, designed to protect Jordanian territory from attack by Assad missiles, has also been moved into the area.

The deployment, seen north of Al-Mafraq by The Times, has been put in place under cover of a military training exercise being held this week, but it will remain there for months.

The added military troops and equipment are designed to increase stability in the region and are not part of the effort to train Syrian rebels or take part in any offensive operations in Syria, the U.S. officials said, speaking on condition of anonymity because they were not authorized to talk