Relations between the United States and Turkey are at a "very critical point," Foreign Minster Mevlüt Çavuşoğlu said Monday ahead of U.S. Secretary of State Rex Tillerson's visit to Ankara.

"We will either fix [U.S.-Turkey] relations, or they'll deteriorate altogether," Çavuşoğlu said in a news conference during the Turkey-Africa 2nd Ministerial Review Conference in Istanbul.

He also commented on Ankara's expectations regarding continuous U.S. support for the PKK terror group's Syrian affiliates the Democratic Union Party (PYD) and its armed wing the People's Protection Units (YPG).

"We don't want promises and pledges from the U.S., we want concrete steps [regarding the YPG]. For us to discuss multiple issues with the U.S., the trust that has been lost needs to be restored. And the cause of the lost trust is U.S. [actions]," Çavuşoğlu added.

The minister said the YPG, who the U.S. supports under the pretext of fighting Daesh, "does not touch" Daesh.

Tillerson is expected to arrive in Turkey on Thursday for official talks over the escalating PKK crisis between Washington and Ankara.

The visit comes amid Turkey's Operation Olive Branch which targets YPG and Daesh terrorists in northwestern Syria's Afrin region.

Relations between the two NATO allies have been strained recently over a number of issues.

Turkey strongly opposes U.S. military support for the Syrian Democratic Forces (SDF), which is dominated by the terrorist PKK-affiliated PYD and YPG, which constitute a serious threat to Turkey's security.

The U.S.' refusal to extradite Gülenist Terror Group (FETÖ) leader Fethullah Gülen, who was a mastermind behind the failed coup attempt on July 15, 2016, is one of the longest-standing disputes between Ankara and Washington.