U.S. troops have begun military exercises in Jordan.
Both Washington and Amman said the "Eager Lion" exercises were not related to the conflict in Syria.
However, Moscow has criticized the drills -- which include F-16 jets and Patriot missiles -- accusing the West of fanning the conflict in Syria.
More than 4,500 American troops, around 3,000 Jordanians, and 500 soldiers from Britain, Saudi Arabia, and other countries are taking part in the exercises, less than 120 kilometers from the Syrian border.
The drills also involve a number of F-18 jets from bases in the Gulf and drills on handling chemical strikes, which Syria's government and rebels have accused each other of carrying out.
Based on reporting by Reuters and AP