ANKARA (Reuters) - U.S. President Donald Trump and Turkey’s Tayyip Erdogan spoke on Saturday and agreed to continue to work toward stronger ties and regional security, Erdogan’s office said, a day after he lashed out at U.S. authorities for indicting one of his ex-ministers.

U.S President Donald Trump (L) welcomes Turkey's President Recep Tayyip Erdogan at the entrance to the West Wing of the White House in Washington, U.S. May 16, 2017. REUTERS/Joshua Roberts

Ties between the United States and its NATO ally have been strained by Washington’s support for the YPG Kurdish fighters in the battle against Islamic State in Syria. Turkey considers the YPG a terrorist group.

Ankara has also been frustrated by what it sees as Washington’s reluctance to extradite the Muslim cleric Fethullah Gulen. Turkey blames Gulen, who has lived in Pennsylvania since 1999, for last year’s failed coup.

“Noting the strategic partnership between Turkey and the United States, the two leaders emphasized the importance of continuing to work together to further strengthen bilateral relations and increase stability in the region,” the Turkish Presidency said in a statement.

The two leaders agreed to meet in New York at the United States General Assembly, scheduled for this month.

The call was notable for its timing, coming a day after Erdogan described a U.S. prosecutor’s indictment against Turkey’s former economy minister as being politically motivated and tantamount to an attack on Ankara.

The former minister, Zafer Caglayan, and the ex-head of a state-owned Turkish bank were charged this week with conspiring to violate Iran sanctions by illegally moving hundreds of millions of dollars through the U.S. financial system on Tehran’s behalf.

The indictment marked the first time an ex-government member with close ties to Erdogan had been charged in the on-going U.S. investigation, which has strained ties between the two countries.

“For the moment, it is impossible to evaluate this within legal logic,” he told reporters on Friday. “I see this step against our former economy minister as a step against the Turkish Republic.

He had also called on Washington to re-think the charges.

“I hope we’ll get a chance to discuss this issue in the United States. You may be a big nation, but being a just nation is something else. Being a just nation requires the legal system to work fairly.”