FILE PHOTO: U.S. President Donald Trump and Turkish President Tayyip Erdogan attend the start of the NATO summit in Brussels, Belgium July 11, 2018. REUTERS/Kevin Lamarque

WASHINGTON (Reuters) - U.S. President Donald Trump told Turkish President Tayyip Erdogan in a phone call on Monday he wants to address Turkey’s security concerns in Syria but stressed the importance that Washington’s Kurdish allies not be mistreated, the White House said.

The phone call came as the two NATO allies worked to iron out differences and discussed ongoing cooperation in Syria to defeat Islamic State militants even as U.S. forces began withdrawing from the country.

In a note on Twitter earlier, Trump threatened Turkey with economic devastation if it attacked a U.S.-allied militia in Syria, comments that drew a sharp rebuke from Ankara and revived fears of a downturn in ties.

The White House said in a statement that Trump and Erdogan had discussed bilateral issues, including “ongoing cooperation in Syria as U.S. forces begin to withdraw.”

“The president expressed the desire to work together to address Turkey’s security concerns in northeast Syria while stressing the importance to the United States that Turkey does not mistreat the Kurds and other Syrian Democratic Forces with whom we have fought to defeat ISIS,” White House spokeswoman Sarah Sanders said in a statement.

U.S. Marine General Joseph Dunford, chairman of the Joint Chiefs of Staff, will meet with his Turkish counterpart on Tuesday to continue consultations, she said.

Turkey said the two discussed the establishment of a secure zone in northern Syria cleared of militia groups. They also emphasized the need to complete a roadmap regarding the Syrian border town of Manbij, the Turkish presidency said.