Sen. Lindsey Graham (R-SC) said in a statement on Syria published Friday that he “looks forward” to soon meeting with Turkish President Recep Tayyip Erdogan.

The statement said the two intend to “discuss common interests and security concerns” in northeastern Syria as the U.S. reportedly prepares to withdraw from the war-torn area.

Graham’s statement begins:

There are millions of Kurds living in Turkey who are vibrant members of Turkish society, contributing to their economy, culture and democracy. But I have long contended that there are elements among the Syrian Kurds that represent a legitimate national security threat to Turkey. Turkey’s concern regarding YPG elements must be addressed in a real way to ensure that Turkey’s borders are secure and are protected from any threats. Any final disposition in Syria must address Turkey’s national security interests and concerns.

The YPG is the Syrian Kurdish People’s Protection Units (their all-woman unit goes by the initials YPJ), America’s closest battlefield ally in Syria. As the majority of the members of the Syrian Defense Forces coalition (SDF), the YPG was largely responsible for the liberation of Raqqa from the Islamic State. Erdogan’s government considers the YPG a “terrorist” group.

Graham said the U.S.’s strategic objectives remain unfulfilled and thus its mission in the area is “not yet complete.” Iran, Russia, and Syrian dictator Bashar-al-Assad must not benefit from a U.S. pullout from Syria, the South Carolina Republican affirmed.

Graham’s statement follows reports indicating the U.S. military has removed some equipment from Syria, signaling the pullout ordered by President Donald Trump is now underway.

“I can confirm the movement of equipment from Syria,” one U.S. official told AFP. “For security reasons, I am not going to provide further details at this time.”

On December 19, President Trump announced that he was withdrawing all 2,000 American troops from the conflict-wracked country, citing the near total defeat of ISIS. Though the removal of troops is not in the cards immediately, withdrawing equipment is a means of showing progress toward this goal, it added.

On Sunday, National Security Advisor John Bolton set out stringent conditions for the proposed withdrawal, saying the defense of allies like the YPG must first be assured.

“We’re going to be discussing the president’s decision to withdraw, but to do so from northeast Syria in a way that makes sure that ISIS is defeated and is not able to revive itself and become a threat again,” Bolton said when meeting Israeli Prime Minister Benjamin Netanyahu in Jerusalem.

Erdogan accused the U.S. national security adviser of making “a very serious mistake” Tuesday by demanding that Ankara guarantee the safety of Kurdish fighters in northeastern Syria before the U.S. withdraws its troops.

A strained morning of negotiation in Turkey, in which Erdogan refused to meet with Bolton, ended without assurances of protection for forces that fought alongside U.S. troops against the Islamic State group, and indeed brought them fresh new threats from Turkey. A spokesman for Bolton said U.S. officials were told Erdogan cited the local election season and a speech to parliament for not meeting with him. The diplomatic setback raised fresh questions about how the U.S. would protect its allies in the fight against ISIS and about the pace of the drawdown of U.S. forces in Syria.

“John Bolton has made a very serious mistake. We cannot make any concessions in this regard,” Erdogan said Tuesday, just before Bolton left the country with tensions between the NATO allies at new highs. He added that Ankara’s preparations for a new military offensive against what the Turkish leader describes as terror groups in Syria are “to a large extent” complete.

A senior administration official said Erdogan’s comments did not reflect President Donald Trump’s understanding of his December 23 conversation with the Turkish leader, days after the U.S. president announced his intent to withdraw American troops from northeastern Syria. Trump “thought he got a commitment from Erdogan” to protect the Kurds, the official said, speaking on the condition of anonymity because the official wasn’t authorized to speak on the record.

The Associated Press and Agence France-Presse contributed to this report.