President Recep Tayyip Erdoğan signaled Sunday a military operation against the PKK terror group's Syrian offshoot Democratic Union Party (PYD) and its armed wing People's Protection Units (YPG) in Syria's Afrin, located at the border with Turkey.

Speaking at the provincial congress of the ruling Justice and Development Party (AK Party) in the central province of Tokat, Erdoğan said that Turkey is determined to fight against PKK terrorists across its borders, as well as as inside the country.

"Turkey will continue the operation to clear its southern border from terror with Afrin. We urge the international community to support Turkey's legitimate efforts," Erdoğan said.

"The slightest harassment from across the border will be seen as a signal flare to start the steps that are needed to be taken," Erdoğan said.

President Erdoğan also said that Turkey does not differentiate between terrorists, and treats all terrorist groups equally no matter where they are located.

According to information obtained by the Anadolu Agency (AA) from local sources, YPG terrorists in northern Syria have reportedly geared up to establish a regular army called the Army of the North with U.S. assistance.

The sources said the U.S. military completed the training of 400 YPG members, following an announcement from the U.S. Central Command (CENTCOM) Commander Gen. Joseph Votel on Dec. 22, 2017, about forming border guard regiments.

Washington reneged on its promise to cease its support for the PKK's Syrian affiliate the Democratic Union Party (PYD) and its armed wing the YPG after Daesh was defeated in Syria, and has substantially increased weaponry and technology support to the group.

Despite the PKK being listed as a terrorist group by the U.S., EU, and NATO, Washington supports the PYD and the YPG as "the most effective partner against Daesh," overlooking their links to the PKK. The support has become a strong factor in the deterioration of ties between the two NATO allies, bringing relations to historic lows in recent years.