The internationally backed Syrian Democratic Forces said it had resumed counter-terrorism operations with US and coalition forces after they were paused due to Turkey's shelling of Kurdish positions in northern Syria.
The US-backed group led the ground offensive with international backing to defeat ISIS in Syria in 2019.
Turkey has been shelling and carrying out air strikes in northern Syria in recent weeks and says it is preparing for a ground invasion against Kurdish groups that it accuses of carrying out a terrorist attack in Istanbul last month. Turkey brands the Kurdish force that makes up much of the SDF a terrorist organisation.
The SDF on Friday said all joint operations with coalition forces had been paused due to the Turkish bombardment and called on the US and West to tell Turkey not to invade the areas under its control.
The SDF has long warned that fighting off a new Turkish incursion would divert resources from protecting a prison holding ISIS fighters or raiding the terrorist group's sleeper cells still waging hit-and-run attacks in Syria.
Simand Ali, an SDF spokesman, told Reuters on Monday that joint patrols and training exercises with the coalition had resumed at the weekend after a decrease in Turkish strikes, with four joint patrols carried out on Saturday and Sunday.
Joint training drills had also resumed, he said.
"At the moment, the atmosphere is semi-positive and allows us to undertake joint operations, but we don't know how long these operations will be possible", he said, given the possibility of a ground invasion.
The US has said it understands Nato ally Turkey's concerns in Syria, but has opposed a ground invasion and said Turkish raids had directly threatened the safety of American personnel.
On Friday, former coalition spokesman Col Myles B Caggins III told The National that Turkish shelling had killed SDF commanders including Jiyan Tolhildant, a senior leader in the most elite special operation anti-terrorist task force, as well as a number of anti-terrorist troops trained by the US Commando Special Forces in Syria.
The US-led coalition has backed the SDF with air strikes, military equipment and advisers since 2017, first helping it wrest back territory from ISIS and then supporting clearing operations against militant sleeper cells.