Although U.S. troops have been withdrawn from northeastern Syria, new Joint Chiefs Chairman Gen. Mark Milley said Friday that the Turkish military had been given the exact locations of all U.S. forces in Syria and added that they have "the right to defend themselves".
Iran meanwhile offered on Saturday to engage Syrian Kurds, Syria's government and Turkey in talks to establish security along the Turkish-Syrian border following Turkey's military incursion into northern Syria to fight Kurdish forces. "The Americans have been in constant contact with this party up until now", he told Reuters by phone.
"Turkey wants us off the the entire border region to a depth of 30 kilometres", he said.
The shells, which were fired at around 9pm on Friday, landed within a few hundred yards of the base on Mistenur Hill, according to US officials.
Turkish soldiers secure the area as Turkish military vehicles carry tanks to the Syrian border in Akcakale, Turkey.
Brett McGurk, a former special envoy in the campaign against ISIS who worked for both the Obama and Trump administrations, wrote on Twitter: '[The shelling] was not a mistake'. We will take action. The case had roiled relations with Turkey and prompted an outcry from US evangelical groups.
However, Ankara denied on Saturday targeting a U.S. base in northern Syria.
Turkey and its allied fighters began the offensive on Wednesday to push back the Kurdish Peoples' Protection Units (YPG), the backbone of the SDF, from its border. Navy Capt. Brook DeWalt, a Pentagon spokesman, said in a statement that the USA troops "came under artillery fire" but were unharmed and that there was an explosion.
Uncertainty in the Syria's Kurdish held territories after the U.S.' departure has caused tens of thousands of civilians to flee.
"The (Syrian rebel) national army took control of the town centre this morning".
Omar said it has been involved in the autonomous administration for northern Syria. "U.S. forces have not withdrawn from Kobani", it said.
Turkey's Defense Ministry said it had taken all measures to ensure that no USA base was damaged while it responded to harassment fire that originated near a US base close to Kobane. "As a result of the transmission of the issue to us by the United States, the fires ceased".
Prisoners of the Islamic State militant group (ISIS) held in Kurdish-controlled areas of north-eastern Syria are no longer the responsibility of the Syrian Democratic Forces (SDF), a spokesman for the group said.
Turkey said its forces did not shoot back at the USA base and took all precautions to prevent any harm to it while it was responding to YPG fire from a nearby area.
The Chairman of the Joint Chiefs of Staff General Mark Milley told reporters at the Pentagon earlier on Friday that Turkey had been told of US positions in Syria, 'down to explicit grid coordinate detail'.
The Kurdish-led Syrian Democratic Forces (SDF) now hold thousands of suspected IS prisoners.
Although U.S. troops had no intention of firing on Turkey, a North Atlantic Treaty Organisation ally, the Pentagon noted they had the right to defend themselves.
The president repeated that going into the Middle East was the worst decision ever made by the United States, noting the expensive war and the loss of life over weapons of mass destruction that did not exist.
He added that "we retain the right to self-defense - that's clear and unambiguous".