Turkey is threatening new incursion into Syria

ISTANBUL — The Turkish president is threatening to mount a new incursion into northern Syria, accusing the United States of failing to tackle the security threats Turkey faces in the region.

Turkish commando units were deploying Friday to the border with northeastern Syria, the Turkish news media reported, raising the possibility of an inadvertent confrontation with U.S. troops operating in the same area.

NATO allies, Turkey and the United States both oppose Syrian President Bashar Assad. But they back rival local forces on the ground in Syria: Turkey supports the Free Syrian Army, a mainly Arab rebel force, while the United States is allied with the Kurdish-led Syrian Democratic Forces.

In a phone call with U.S. President Donald Trump, Turkey’s President Recep Tayyip Erdogan expressed concerns Friday about the actions and presence of the Kurdish militia in northeastern Syria, the Turkish president’s office said. Erdogan has repeatedly demanded that U.S. forces stop supporting the Syrian Kurdish fighters.

“If there is a threat against us there, which there is, the response to this threat will be immediate,” Erdogan said Friday in a speech to representatives of the Organization of Islamic Cooperation in Istanbul. “Either they will demolish those terror groups or we will,” he added in a reference to the United States and its Kurdish allies.

A Pentagon spokesman, Cmdr. Sean Robertson, has warned that any unilateral military action in Syria’s northeast would be unacceptable and a source of grave concern, “particularly as U.S. personnel may be present or in the vicinity.”

In addition to some 2,000 military personnel, a team of up to 20 American civilians helps run stabilization programs in northeastern Syria, working to restart utilities and clear rubble in areas captured from the Islamic State.

Turkey, which has been fighting the separatist Kurdistan Workers’ Party, or PKK, in Turkey for three decades, has accused the United States of bolstering the group by arming and training its Syrian affiliate, the YPG, which forms the backbone of the Syrian Democratic Forces. The United States considers the PKK a terrorist group, but says the YPG is the force in Syria most capable of fighting the Islamic State.