Turkish Defense Minister Fikri Işık will meet his U.S. counterpart Jim Mattis on Wednesday in Brussels as the tension between the two countries once again rose after the U.S. reaffirmed its support to the PKK's Syrian offshoot the armed People's Protection Units (YPG).

The Defense Ministry said in a statement on Tuesday that Işık and Mattis will hold a bilateral meeting a day before the NATO summit at the ministerial level.

The two leaders are likely to discuss Turkey's concerns over the U.S.'s support to the YPG, especially after Mattis said that the U.S. will continue to provide weapons to the YPG after the battle against Daesh ends in northern Syria's Raqqa province.

Describing American reassurances to Turkey that the U.S. will take back weapons it has given to the YPG after the Daesh fight, Mattis said a timeline on that return depends on when and where the next mission is. He also gave a note of caution when asked if all the weapons will be returned.

"We'll do what we can," the defense secretary told reporters traveling with him to Germany.

Turkey considers the PKK's Syrian offshoot the Democratic Union Party (PYD) and the YPG to be affiliates of the PKK, a proscribed terrorist organization according to the U.S., Turkey and the EU. The U.S. and the EU do not share Ankara's concerns regarding the YPG. Continuous U.S. support for the YPG has caused tensions in relations between Washington and Ankara while the former says that supporting the YPG is the only option to defeat Daesh and the latter says an alternative could be found with local Arab tribes, backed by countries in the region, rather than supporting and arming "a terrorist group."