The U.S. has begun pulling all troops from Syria in the chaos set off by Turkey's invasion, senior administration officials said Monday.

A "deliberate withdrawal from Syria" by the estimated 1,000 U.S. troops, who had previously been supporting the Syrian Democratic Forces in the fight against ISIS, came about because of the refusal of Turkish President Recep Tayyip Erdogan to call off the attacks, the official said.

One of the officials said a small contingent of U.S. troops would "continue to stay for the time being" at the Al Tanf Garrison on the Jordanian border. The location is well to the south of the fighting, but the intent is to have all U.S. forces and their equipment pulled from Syria, officials said.

The announced withdrawal appears to signal an end to U.S. efforts to combat ISIS in Syria, while avoiding involvement in that nation's civil war. But the officials said Erdogan was being pressed to reverse course and agree to a ceasefire.

Without giving details, President Donald Trump stated earlier that the troops being pulled out of Syria would remain in the region and continue to work in unspecified ways against a resurgence of ISIS.

About 50 U.S. troops pulled out of northeastern Syria ahead of Turkey's invasion, which began Oct. 9.

Other U.S. troops were withdrawn from a broader swath of northern Syria following an Oct. 11 incident in which Turkish artillery fire came near a U.S. observation post in the border town of Kobane.

The initial withdrawals suggested that the troops were repositioning to the south, but administration officials said the plan now is to have all U.S. troops out of the country while the U.S. seeks to cobble together a ceasefire on an increasingly complicated battlefield.

One of the officials said the U.S. would continue to "pursue a negotiated settlement," and a senior delegation, possibly headed by Vice President Mike Pence, would soon be departing for Ankara.

More troops and fighter jets are headed to Saudi Arabia in response to Iran's continued antagonistic actions in the Middle East, Defense Secretary Mark Esper and Chairman of the Joint Chiefs of Staff Army Gen. Mark Milley announced Friday.

The Defense Department said it will send two fighter squadrons, an Air Expeditionary Wing, two Patriot missile batteries, and one Terminal High Altitude Area Defense system, known as THAAD, to act as a force stabilizer, bringing the count to 3,000 additional troops that have had deployments authorized or extended in the last month, the top officials said.

A department official told Military.com that while Esper has authorized the deployments, the U.S. Air Force is still determining what type of fighters are available to deploy at Central Command's request. The latest deployment will use 2,800 new U.S. personnel, in addition to the 200 troops that deployed on Sept. 26 to support a single Patriot air defense battery and four Sentinel 3D Radars.

Earlier this year, F-15C Eagles deployed to the Middle East to take over the F-22 Raptor's persistent mission in the region. The F-35 fifth-generation fighter, which first deployed to the theater in April, began multiple "show of presence" flights alongside the F-15s over the Persian Gulf in May.

In response to Iranian provocation since May, Esper said the U.S. has moved "an array of additional capabilities to the region" including Airborne Early Warning aircraft squadrons, maritime patrol aircraft squadrons, multiple Patriot batteries, B-52 Stratofortress bombers, a U.S. Navy carrier strike group, an amphibious transport dock, unmanned aircraft, in addition to supplemental personnel.

"This has involved the deployment of roughly 14,000 additional U.S. forces to the region," he said, adding there are additional military units on alert ready for these regional missions "if necessary."

HAMPTON, Ga. — The Royal Canadian Air Force says one of its pilots is safe after he had to eject from his plane just before an aerobatics show in the United States.

The Canadian Forces Snowbirds, the 431st Air Demonstration Squadron, said the jet Capt. Kevin Domon-Grenier, Snowbird 5, crashed into an unpopulated area Sunday near Hampton, Georgia, and no one on the ground was injured.

The Snowbirds, Canada’s version of the U.S. Thunderbirds, were set to perform at the Atlanta Air Show. Event organizers said they canceled the rest of Sunday’s show after the crash.

The Snowbirds fly the CT-114 Tutor, which was added to the Canadian fleet in the mid-1960s to train student pilots, a role it served in til the early 2000s. The 32-foot-long jets, with a wing span of 36.5 feet, are powered by a single General Electric J85-CAN-40 turbo jet.