U.S. Secretary of State Rex Tillerson has expressed "profound concern" over the detention of U.S. diplomatic staff in Turkey, the State Department said on October 11.
In a phone conversation with Turkish Foreign Minister Mevlut Cavusoglu, Tillerson also called on the Turkish government to present evidence behind the accusations against the employees, the department said.
The United States suspended most visa services for Turkish citizens after authorities arrested two Turkish employees at the U.S. Consulate in Istanbul on charges of espionage over the weekend. Turkey retaliated by halting visas services in the United States.
The phone conversation between Tillerson and Cavusoglu was the first since the diplomatic crisis between the two NATO allies broke out. It lasted more than 30 minutes, Turkish media said.
Turkish leaders struck a conciliatory tone in comments earlier on October 11.
Turkish Prime Minister Binali Yildirim said in Ankara, "We hope that relations between two allies will return to normal in a short time.... At a time when global and regional tensions are escalating, we are not going to leave common sense behind."
Turkish Deputy Prime Minister Mehmet Simsek said on a visit to Washington that Turkey is "safeguarding" the U.S. employees and "we don't want this dispute to last more than a second."
U.S. Defense Secretary Jim Mattis said the dispute has not affected the U.S. military's relationship with Turkey's armed forces.