(CNN) —  

The US-backed Syrian Democratic Forces have announced a pause in their campaign against ISIS following clashes between the SDF and Turkish forces, according to two US military officials and a statement from the SDF.

The US-led coalition fighting ISIS has conducted scores of air and artillery strikes in recent weeks as it has sought to drive ISIS from its last stronghold east of the Euphrates River in Syria.

ISIS has been driven to just a few towns in the area and the US and its coalition allies conducted 184 air and artillery strikes last week targeting the terror group’s last remaining territory, striking command and control centers, weapons caches and vehicles.

The halting of the operation is a major setback for the US and its allies and comes after Turkey threatened a new military operation targeting the Kurdish-led SDF.

Pentagon spokesman Cmdr. Sean Robertson told CNN on Tuesday that the US was encouraging “all parties to avoid escalation and focus on the most important task of defeating ISIS,” adding that “the campaign against ISIS is not over and the fight remains very difficult.”

“We are aware of Turkish statements about a planned offensive into northeast Syria and have been in touch with Turkey and the SDF to de-escalate the situation,” he added, while saying that the US military was “working closely with the SDF who are in the midst of offensive operations against ISIS in the Middle Euphrates River Valley,” calling the US allies “a committed partner against ISIS.”

The approximately 50,000-strong Syrian Democratic Forces are a mix of Kurdish and Arab fighters and have been the primary ground force fighting ISIS in much of the country.

The US has some 2,000 troops in Syria, many of whom work with the SDF.

“Turkish attacks in the north and ISIS attacks in the south against our troops had forced us to stop our current operation temporarily against ISIS in the last pocket of it,” the SDF said in a statement.

“We also call the international community to condemn the Turkish provocations in the safe areas in Syria, and we demand our partners in the International Coalition to show a clear attitude and stop Turkey from launching attacks on the region,” the statement added.

Two US military officials confirmed that the Turkish military had shelled SDF positions in northern Syria in recent days.

Turkey sees Kurdish elements of the SDF as linked to the separatist group the Kurdistan Workers’ Party (PKK), which the US identifies as a terrorist group.

US support for the SDF has caused major tensions between Washington and Ankara, but those tensions appeared to be abating somewhat after the US and Turkey negotiated a “road map” in regard to the northern Syrian town of Manbij.

As part of that agreement, the US was to convince Kurdish elements of the SDF to withdraw from Manbij and US and Turkish troops were to conduct joint patrols in the town’s vicinity.

Training for the patrols was recently concluded and three US defense officials told CNN on Tuesday that the joint patrols were due to begin in “a matter of days.” It remains to be seen whether the renewed tensions between Turkey and the SDF will interfere with those plans.