U.S. Forces Will Remain in Syria After Battle With ISIS Ends

American forces will remain in Syria even after the last remnants of the Islamic State militant group are eradicated, signaling a shift in U.S. policy that further complicates the political climate in Syria amid its seven-year civil war

Defense Secretary Jim Mattis told reporters at the Pentagon on Monday that U.S. forces will stay in Syria to provide training to local forces in an effort to ensure stability within the region, a decision that seems to run counter to past statements from President Donald Trump, who has repeatedly threatened to withdraw American forces from the region.

The news out of the Defense Department comes on the same day that John Bolton, the White House national security adviser, told reporters at the U.N. headquarters in New York that U.S. forces will remain in Syria as a deterrent to Iranian aggression.

"We're not going to leave as long as Iranian troops are outside Iranian borders and that includes Iranian proxies and militias," Bolton said, according to the Associated Press.

Bolton said Iran was responsible for orchestrating attacks in Syria and Lebanon using proxy militants and was guilty of shooting down a Russian military aircraft last week, contradicting claims made by the Kremlin and Syrian President Bashar al-Assad who said Israel was responsible for the incident.

The allegation of Israeli involvement drew sharp criticism from Secretary of State Mike Pompeo. "We're finding lots of places where they're working against American interests and we will hold them accountable for so doing," he said.

In response, however, Russia vowed on Monday to bolster Syria's air and missile defense systems amid rising tensions with U.S. allies, according to Newsweek. Pompeo went on to criticize Russia's delivery of S-300 missiles to Syria, which are capable of intercepting multiple air targets at a distance of more than 150 miles away.

The U.S.-led coalition expressed concern over Russia's newer anti-aircraft system in an emailed statement to Newsweek, saying, "The Coalition will continue to de-conflict air and ground operations with Russian military officials as we support our partners in the lasting defeat of ISIS in northeast Syria."

"The safety of all Coalition personnel is of the utmost importance so anytime new equipment to the region is introduced, it is a concern, but we will continue our professional military exchanges to prevent accidental targeting or unnecessary escalation between Russian-backed Syrian regime forces and Coalition-backed Syrian Democratic Forces," coalition spokesperson U.S. Army Colonel Sean Ryan said.

Bolton had tried to negotiate a deal with Russia to support an Iranian withdrawal from Syria; however, the downing of the Russian surveillance aircraft killed any deal.

"Regime change in Iran is not the administration's policy," Bolton told reporters. "What we expect from Iran is massive changes in their behavior. And, until that happens, we will continue to exert what the president has called maximum pressure. That's what we intend to do."

Mattis said he spoke to Bolton twice on Monday, telling reporters that there is "no daylight" between him and Bolton's reasoning on keeping a residual force in Syria.

Tom O'Connor provided additional reporting.