President Trump will meet with Turkish president Recep Tayyip Erdogan on May 16 to discuss the U.S.-Turkey relationship and working together to combat terrorism, the White House said in a statement.

The meeting will take place at the White House.

The meeting will not be without controversy -- in April, Turkey voted to greatly expand Erdogan's powers as president in a referendum that critics decried as tainted. Under the new system, the president will be able to appoint ministers and senior government officials, issue decrees and declare states of emergency.

Opposition parties have complained of a series of voting irregularities, including an electoral board decision to accept ballots that did not bear official stamps, as required by Turkish law. International monitors from the Organization for Security and Cooperation in Europe said the move undermined safeguards against fraud.

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After Erdogan's victory, Mr. Trump called him to congratulate him on the referendum win. That drew harsh criticism that he was turning a blind eye to leaders who rule through autocracy.

Turkey has been a close ally in the fight against the Islamic State of Iraq and Syria (ISIS) group, given its proximity to Iraq and Syria.