Oct. 7 (UPI) — In a highly controversial move, the White House has said it will remove U.S troops from northern Syria ahead of a Turkey military advance to expel Kurdish forces from the region.

The White House issued a statement late Sunday following a phone call between U.S. President Donald Trump and Turkish President Recep Tayyip Erdogan, in which it said the administration will neither support nor interfere with Turkey’s mission.

“Turkey will soon be moving forward with its long-planned operation into Northern Syria,” the statement read. “The United States forces, having defeated the [Islamic State] territorial ‘Caliphate,’ will no longer be in the immediate area.”

Erdogan said a day earlier the Turkish military was ready to mount the attack.

The Trump administration’s tacit approval of Turkey’s military incursion represents an about-face of U.S. policy. In August, Secretary of State Mike Pompeo warned Turkey against conducting such an action, stating there would be “potentially devastating consequences.”

Turkey, a key NATO ally, has been threatening to attack the Kurdish-led, U.S.-backed Syrian Democratic Forces — as it’s headed by the YPG militia, the Syrian version of the Kurdistan Worker’s Party, which Ankara considers a terrorist organization.

The White House decision generated sharp responses Monday.

“This impulsive decision by the president has undone all the gains we’ve made, thrown the region into further chaos. Iran is licking their chops,” Republican South Carolina Sen. Lindsey Graham, who’s been a regular supporter of Trump’s, told Fox News. “If I’m an [IS] fighter I’ve got a second lease on life. So to those who think [IS] has been defeated, you will soon see.”

“The president has sided with authoritarian leaders of Turkey and Russia over our loyal allies and America’s own interests,” former Secretary of State Hillary Clinton said. “His decision is a sickening betrayal both of the Kurds and his oath of office.”

Brett McGurk, former U.S. envoy to the global IS-countering coalition, called it a gift to Russia, Iran and the Islamic State.

“Donald Trump is not a commander in chief,” he tweeted. “He makes impulsive decisions with no knowledge or deliberation. He sends military personnel into harm’s way with no backing. He blusters and then leaves our allies exposed when adversaries call his bluff or confronts a hard phone call.”

Trump answered his critics by saying a U.S. withdrawal in Syria was long overdue.

“I held off this fight for almost 3 years, but it is time for us to get out of these ridiculous endless wars, many of them tribal, and bring our soldiers home,” he said. “WE WILL FIGHT WHERE IT IS TO OUR BENEFIT, AND ONLY FIGHT TO WIN. Turkey, Europe, Syria, Iraq, Russia and the Kurds will have to figure the situation out.

“We are 7,000 miles away and will crush ISIS again if they come anywhere near us!”

The SDF, which was a close partner to the United States in the fight against IS in Syria, was integral last spring to recapturing the terrorist organization’s final so-called caliphate in the war-torn country. In late August, the United States and Turkey signed an agreement to install a security mechanism along the Turkey-Syria border to prevent the Islamic State from a resurgence in the area. A main part of the agreement consisted of the SDF removal of its military fortifications and combat troops to address Turkey’s security concerns.

SDF said following the U.S. announcement Sunday that Erdogan has now transformed the agreement into “a mechanism of death” and “the stable & secure region into a zone of conflict and permanent war.”

Based on our confidence in the #US efforts in the Security Mechanism agreement, we implemented all our commitments to remove military fortifications between Tal Abyad & SereKaniye, withdraw combat forces with heavy weapons, risking a security vacum as a result of the agreement.— Coordination & Military Ops Center – SDF (@cmoc_sdf) October 7, 2019

SDF spokesman Mustafa Bali tweeted Monday the Kurdish people are owed an explanation for why the United States failed to fulfill its commitments.

“U.S. forces on the ground showed us that this is not how they value friendship & alliance,” SDF spokesman Mustafa Bali said. “However, the decision by the [president of the United States] is about to ruin the trust and cooperation between the SDF and U.S. built during the fight against ISIS. Alliances are built on mutual trust.”

In an interview with Voice of America, Bali said the SDF is taking the threat of attack “extremely” seriously.

“We fear that mass killings would be committed against our people if Turkish forces invaded this part of Syria.”

The United States also said Sunday Turkey assumes responsibility for potentially thousands of foreign-born IS fighters from SDF custody.

The announcement came six days after the U.S. Defense Department released its fiscal year 2020 joint strategic oversight plan, which said the Pentagon “supports the leadership of the Syrian Democratic Forces.”