"USA forces have not withdrawn from Kobani", it said.
One Army officer who has deployed to northeastern Syria and has knowledge of the situation said that multiple rounds of 155mm fire were launched from Turkey's side of the border and that they had a "bracketing effect" in which shells landed on both sides of the USA outpost. "These are very powerful sanctions". "But we can shut down the Turkish economy if we need to".
Mnuchin said Trump was concerned about Turkey's potential targeting of civilians and wants to make clear that Turkey can not "allow even a single ISIS fighter to escape".
US troops near the northern Syrian border came under artillery fire from Turkish forces, although no injuries were reported, the US Department of Defense said Friday.
Turkey's president has vowed to continue his offensive in Syria, and claims to have taken the border town of Ras al-Ain.
Later at the Pentagon, a US official told several news outlets that the source of the shelling in Kobane had not yet been confirmed.
The Army officer with knowledge of Syria said that Turkish forces previously have launched artillery over the border near USA forces.
"Blackmail and threats will never deter Turkey from its just cause", Ibrahim Kalin wrote on Twitter.
"I'm not seeing any indication or warnings of any planned stoppage of their military activity", said Milley, the top U.S. military officer.
An AFP correspondent in the area said Turkish troops and allied Syrian rebels had entered the town but had yet to capture it.
The Kurdish-led Syrian Democratic Forces, who were the main ground partner in the US-led campaign against the Islamic State group, have taken mounting losses against the vastly superior firepower of the Turkish army.
He warned that the Turkish operation was opening the way for IS to regroup.
"You are leaving us to be slaughtered", the commander of the Kurdish-led forces told a senior U.S. diplomat.
But the Kurds say that the Turkish invasion, which has led to an exodus of civilian residents, Arab as well as Kurdish, amounts to an attempt to redraw the ethnic map fo the region at their expense. The Kurds have detained thousands of ISIS prisoners in the area.
The alliance would bring in Russian warplanes to enforce a no-fly zone over northeast Syria, which would hinder Turkey's ability to perform air strikes.
Turkey denied opening fire on U.S. troops and said the attack was on "terrorist positions".
Esper said he was repositioning additional troops around the region "to assist with force protection as necessary".
Earlier Friday, the U.S. warned that Ankara could face "powerful sanctions" if its operations target civilians.
SDF forces currently hold some 12,000 ISIS militants in their prisons following years of helping the U.S.in quashing the group's influence, but now that the US has effectively withdrawn its support and allowed a Turkish incursion into their territory, the Kurdish-led group must focus its efforts on protecting its people and borders, head spokesman Mustafa Bali told Rudaw.