By Eric Schmidt

WASHINGTON - The military said on Friday that it was sending Bradley fighting vehicles, advanced radar and more fighter jet patrols to northeast Syria, three weeks after a Russian armored vehicle rammed an American ground patrol and injured seven American soldiers.

The reinforcements, which add about 100 troops to the more than 500 U.S. forces already there, represent a show of force in response to the clash last month that caught American commanders off guard. They are also likely to escalate tensions between the two rival powers in the country's hotly contested northeast.

"These actions are a clear demonstration of U.S. resolve to defend coalition forces," Capt. Bill Urban, a spokesman for the military's Central Command, said in an email, "and to ensure that they are able to continue their defeat-ISIS mission without interference."

The new deployment came on the same day that President Trump declared that American troops "are out of Syria," except to guard the region's oil fields. "Other than that, we are out of Syria," Mr. Trump said at White House news conference, making no mention of what the Pentagon says is the main mission there: to help its Syrian Kurdish allies fight remnants of the Islamic State.

The deployment includes a handful of Bradley fighting vehicles - the same that were dispatched for a month to the region last fall - as well as Sentinel radars to track Russian helicopters, and increased fighter jet and Apache helicopter gunship patrols to support American ground forces. It has been in the works since the altercation in Syria revealed the latest Russian test of American military resolve in the region and around the world.

Democrats immediately seized on the episode as the latest example of Mr. Trump's failure to challenge Russia's increasing aggressions toward the West, including interfering in this year's general election and putting bounties on American troops in Afghanistan.