President Trump has ordered the withdrawal of all 1,000 U.S. troops from northern Syria, Defense Secretary Mark Esper said Sunday, amid evidence that Turkey’s military and Turkish-backed militia aim to press father into Syria than expected. Trump's order arrived after Turkish forces fired artillery near U.S. troops, and after ISIS detainees and family members had escaped from a key detention facility, according to Syrian Democratic Forces, or SDF, officials.

Hours after Esper spoke on CBS News’ Face the Nation, the top SDF commander wrote in Foreign Policy that the American retreat left him no choice but to request help from Russia and Syrian President Bashar al-Assad.

Esper said Trump gave him the order in a Saturday evening phone call.

“It’ll be a deliberate withdrawal and we want to conduct it as safely and quickly as possible,” he said. “We want to make sure we deconflict a pullback of forces. We want to make sure we don't leave equipment behind. So I'm not prepared to put a timeline on it, but that's our general game plan.”

After Trump's surprise Oct. 6 decision to move U.S. forces so Turkey could invade Syria, U.S. defense officials had said that no more than 100 U.S. troops in the northern corridor would need to be moved. Joint Chiefs Chairman Gen. Mark Milley said on Friday that the United States was withdrawing from just two outposts in a limited area, and not abandoning the SDF or its fight against ISIS elsewhere in the country.

But then Turkish President Recep Tayyip Erdogan appeared to change his plan, Esper said.

“Despite our opposition, they decided to make this incursion into Syria. And at this point in time in the last 24 hours we learned that they likely intend to expand their attack further south than originally planned and to the west,” he said.

Esper didn’t say where the 1,000 U.S. troops in Syria would go, whether elsewhere in Syria or out of the country.

The defense secretary said Turkish-backed forces were executing Syrian prisoners, citing U.S. intelligence.

“It's terrible. It's a terrible situation. We condemn it,” he said. “We don't know exactly who they all are and what they're doing. But we're hearing the same reports from the battlefield as well…. It appears to be, if true, that they are — would be — war crimes.”

Adding to the confusion, Trump has made a series of contradictory statements. On Oct. 7, Last week, he denied that he gave Erdogan a green light to attack the SDF, tweeting this threat: "if Turkey does anything that I, in my great and unmatched wisdom, consider to be off limits, I will totally destroy and obliterate the Economy of Turkey (I’ve done before!)" But on Sunday, he tweeted, “Turkey considers the PKK the worst terrorists of all. Others may want to come in and fight for one side or the other. Let them!” Just minutes later, he added that the U.S. Treasury Department was “ready to go” on sanctions.

Treasury Secretary Steve Mnuchin said Sunday on ABC’s This Week, "We've put them on warning. The president has authorized me to effectively shut down the entire Turkey economy and we can do that at a moment's notice on his command."

Turkish advance

There are conflicting media reports about the extent of Turkish forces' advance into Syria. Turkish state-run media outlet Anadolu news agency claimed that Turkish forces have captured the town of Suluk, about 10km south of the Turkish border.

Turkey has seized control of the M4 highway that runs across northeastern Syria and serves as a vital supply route in and out of Syria from Iraq, the Washington Post reported on Sunday.

Turkey also has continued shelling in and around the town of Ain Issa, which served as a headquarters to the Kurdish-led administration in the area.

Kurdish forces are looking to make a deal with the Assad regime in Damascus and its Russian backers for a no-fly zone, CNN and several outlets reported Saturday. If they are successful, a NATO ally might soon be in direct conflict with Russia.

Turkish artillery brackets U.S. positions

On Friday, Turkish forces shelled an area near the majority-Kurdish city of Kobani, where between were based. The 155mm rounds appeared to be deliberately aimed to bracket some 15 to 100 U.S. Special Forces soldiers, U.S. military officials told the Washington Post.

Esper, however, declined to call it a deliberate targeting by Turkey.

“We gave them the location of our forces [but] there’s a fog out there, things happen,” he said.

Brett McGurk, the president’s former envoy to Syria and the ISIS conflict, continued his public opposition to the president’s shift and is sounding warnings about its dire results for Syrians, U.S. troops, and U.S. policy interests. “Turkey knows all of our locations down to the precise grid coordinate as confirmed by SECDEF and CJCS only two hours ago. This was not a mistake,” he said in a tweet.

Turkish forces have fired on a declared U.S. military outpost in northern Syria. Turkey knows all of our locations down to the precise grid coordinate as confirmed by SECDEF and CJCS only two hours ago. This was not a mistake. — Brett McGurk (@brett_mcgurk) October 11, 2019

U.S. lawmakers, former diplomats, and others have shown growing frustration with the Turkish invasion. Sen. Lindsey Graham, R-S.C, a close Trump ally, has been pushing for tough new sanctions on the Turkish regime.

Richard Haass, president of the Council on Foreign Relations, tweeted: “Long overdue to give up fiction that Erdogan’s Turkey is an ally in practice. US should withdraw all nuclear weapons, reduce reliance on Turkey’s bases, and restrict intelligence sharing and arms sales. Should also articulate red lines in Syria.”

Long overdue to give up fiction that Erdogan’s Turkey is an ally in practice. US should withdraw all nuclear weapons, reduce reliance on Turkey’s bases, and restrict intelligence sharing and arms sales. Should also articulate red lines in Syria. https://t.co/rWB0AhwRS3 — Richard N. Haass (@RichardHaass) October 13, 2019

Prison break

Aid workers and SDF forces told the Post that 785 people “affiliated with the Islamic State” have escaped from a camp near there, a report backed up by AP. One SDF commander told New York Times reporter Rukmini Callimachi that all of the detained ISIS fighters and their families had fled.

An SDF commander has confirmed to me that the Ain Issa camp has fallen and all the detainees (a population of thousands that includes ISIS supporters, ISIS relatives and civilians) have fled. “An unbelievable mess,” the commander said. Latest message: pic.twitter.com/yDehTSKkux — Rukmini Callimachi (@rcallimachi) October 13, 2019

The prospect of ISIS prisoner escapes was of great concern to the Pentagon and other Syria watchers. Michael Nagata, a retired Army lieutenant general who played a key role in the early anti-ISIS efforts by helping to train and equip the SDF, said it would be “impossible to calculate” the intelligence loss as ISIS detainees slipped away.

Humanitarian crisis

International aid organizations say a humanitarian crisis has quickly developed with reports of 100,000 to 200,000 being displaced by the incursion ordered by Turkey’s President Recep Tayyip Erdoğan. Some 130,000 people have been displaced from the rural areas near the fighting, the U.N. said in a statement.

On Saturday evening, the White House announced that it had released $50 million in stabilization assistance to “provide emergency financial assistance to Syrian human rights defenders, civil society organizations, and reconciliation efforts directly supporting ethnic and religious minority victims of the conflict.”