According to a statement from Lieutenant Colonel T.G. Taylor, spokesperson of the U.S. Central Command, the deployment will take place before this month's multinational training exercise in Jordan, codenamed Eager Lion. The systems will take part in the exercise, but it is understood that they may stay in Jordan after the drill.

"In order to enhance the defensive posture and capacity of Jordan, some of these assets may remain beyond the exercise at the request of the government of Jordan," Taylor said.

The Patriot missiles were originally expected to be sent from their base at Ft. Bliss, Texas, but the senior official said they may simply be redeployed from Patriots already in the Middle East. Jordan does not face a Scud missile threat from Syria, but the deployment comes amid growing concern that some Syrian missiles are being shipped to Hezbollah and could be used to attack targets across the region.

Separately from the exercise, the United States is sending 200 military planners from the headquarters of the 1st Armored Division at Fort Bliss to Jordan to assist in long-term planning with Jordanian forces in case a chemical weapons crisis erupts, or if a wide scale humanitarian relief mission is ordered.