AMMAN: The U.S. military has moved a new truck-mounted, long-range rocket launcher from Jordan to a U.S. base in Tanf, Syria near the Iraqi and Jordanian borders, stepping up its presence in the area, two regional intelligence sources said on Wednesday.

They said the HIMARS (High Mobility Artillery Rocket Systems) were now in the desert garrison that has seen a build-up in military equipment in recent weeks as tensions escalate after the U.S.-led coalition struck Iranian-backed forces to prevent them advancing towards the Tanf base.

"They have arrived now in Tanf and they are a significant boost to the U.S. military presence there," one senior intelligence source said, without elaborating, but adding that the HIMARS had already been deployed in northern Syria with U.S. backed forces battling ISIS militants.