President Recep Tayyip Erdoğan held a phone call with U.S. President Donald Trump over Saudi journalist Jamal Khashoggi murder, FETÖ investigations in U.S., anti-terror fight in Syria and bilateral relations, the Turkish presidency said Friday.

Presidents agreed that all aspects of Khashoggi killing must be uncovered and the case should not be covered up.

Erdoğan and Trump also stressed importance of closer cooperation between Ankara and Washington in fight against all terror groups.

The two leaders also discussed bilateral ties, ongoing legal cases in the United States and developments in Syria, the presidency said, adding that they had discussed the rapid completion of a roadmap in Syria’s Manbij.

Erdoğan also conveyed to Trump Turkey’s expectation that the United States would end its support for the PKK’s Syrian affiliate, People People’s Protection Units (YPG), the presidency said, an issue that has long infuriated Ankara and strained ties between the NATO allies.

The U.S. has been militarily supporting and cooperating with the Syrian Democratic Forces (SDF), which is an umbrella group consists mostly of YPG terrorists, under the pretext of fighting against Daesh terror group. This support remains as a source of tension between Washington and its NATO ally Ankara, which has been suffering from the PKK’s decades-old deadly campaign against the state.

The PKK is listed as a terrorist organization by Turkey, the U.S. and the European Union. The PYD and its armed branch the YPG are the PKK’s Syrian affiliates.

Khashoggi, a frequent contributor to The Washington Post, was killed Oct. 2 inside the Saudi Consulate in Istanbul.

After weeks of denying any involvement in the crime, Saudi Arabia later admitted that Khashoggi had been killed inside the consulate but claimed the Saudi royal family had no prior knowledge of any plot to murder the journalist.

His body has yet to be returned to his family amid reports that it was chemically dissolved.