The U.S. said Monday it is working to set up a telephone call between President Donald Trump and his Turkish counterpart, Recep Tayyip Erdogan, after Erdogan's electoral victories. 

White House spokeswoman Sarah Sanders said the call would focus on reaffirming the "strong bond" between Washington and Ankara. She did not disclose when the call might take place. 

"We encourage Turkey to take steps to strengthen its democracy and continue progress toward resolving issues in the bilateral relationship,” she told reporters.

Turkey on Sunday went to the polls for presidential and parliamentary elections in which Erdogan won the Turkish presidency, according to preliminary results. 

With 99.6 percent of the ballot boxes opened, Erdogan is leading with 52.58 percent of the vote while his closest rival, Muharrem Ince, is lagging behind at 30.64 percent.

In Sunday’s parliamentary polls, the People's Alliance -- a coalition of Erdogan's Justice and Development (AK) Party and the Nationalist Movement Party (MHP) -- won 53.6 percent of the vote.

Several world leaders have sent Erdogan congratulations following the victory, including German Chancellor Angela Merkel and British Prime Minister Theresa May. 

The UN separately told Anadolu Agency that Secretary General Antonio Guterres "looks forward to continuing cooperation with Turkey on an extensive range of issues". 

*Betul Yuruk contributed to this report from the United Nations