Turkey’s Prime Minister Binali Yildirim said the United States should withdraw its weapons and support for the Kurdish and Arab forces that just routed ISIS in Syria, calling them a post-war threat to the region and Israel.

Yildirim, who is visiting Washington this week, said that the U.S. justification for arming Syria’s Kurdish YPG forces, and other groups that comprise the U.S.-trained Syrian Democratic Forces, had expired now that ISIS had been defeated.

Turkey considers the YPG a terrorist threat akin to the armed-separatist Kurdistan Workers Party, or PKK. The prime minister said Ankara would not lend his support to the notion of SDF forces, backed by U.S. troops, remaining in control of parts of Syria through post-war stabilization.

“This has had a very negative impact on relations with the United States,” said the prime minister, who is in Washington for meetings with Vice President Mike Pence, members of Congress, and other U.S. officials.

The YPG and PKK “are terrorist organizations, Marxist-Leninist organizations,” he told reporters Wednesday at the Turkish ambassador’s residence, through a translator. “And unfortunately, the friend, the ally of the United States resorted to them as if it needed to.”

Now, he charged, “the rhetoric is different.”

Last month, the top U.S. special operations commander in Iraq and Syria said he believed that the U.S. will need to keep troops in Syria for months to come, as the Syrian Democratic Forces shift security responsibilities for liberated areas to stabilization forces and civilian councils. Maj. Gen. James Jarrard said that the size and type of those forces is a decision for civilian leaders, and that he expected U.S. troops to support the SDF until ISIS is wiped out, and beyond.

“But there’s a long process after that: making sure that we have the security in place, the stabilization efforts in place, to allow the IDPs [internally displaced persons] to return home," Jarrard said in an Oct. 31 Pentagon briefing via satellite from Iraq. "That is all part of the military defeat of Daesh, making sure that we treat the symptoms that allowed Daesh to take over this area in the first place. And we are committed to supporting the SDF throughout that process."

Yildirim rejected that plan. “Where else have we seen this in the world…using one terrorist organization to defeat another terrorist organization?” he said in Washington. “They justified this as a necessity for the United States to neutralize ISIS, and once neutralization was reached they were going to part their ways with this terrorist organization.”

“But there will be a greater threat in the region because YPG, PKK have more weapons, thanks to our American friends. …They have heavy weapons, tanks, artillery,” he claimed. “These weapons need to be taken back so they aren’t used against innocent people.”

Yildirim alleged the U.S. was supplying “heavy and light weaponry,” including 3,500 trucks to both the PKK and YPG. “Then we see attacks happening in Turkey…239 of our soldiers have been martyred and tens of hundreds of our citizens killed by these weapons.”

U.S. military officials have denied aiding the PKK.

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Yildirim also accused Syrian Kurdish fighters of moving beyond the territory of their mission to defeat ISIS, causing additional displaced persons and “raiding oil reserves.”

“I think this is important for the United States to take its action as soon as possible because it is about to face a more dangerous terrorist organization because it has more weapons.”

The prime minister also defended the decision to purchase Russia’s S-400 anti-missile system, saying the United States’ refusal to supply similar systems left them no choice. The deal with Russia, he argued, was necessary for Turkey’s defense and to make NATO’s southern border more secure from attacks. He did not respond directly when asked if Turkey would reconsider the buy in order to improve U.S. relations, but said that France, Italy, and Turkey’s “signatures have been put on the documents in Brussels today,” to buy additional European missiles.

“With the missile system, of course we wanted to get it from NATO members,” he said, but the United States blocked them. “The fact that we have started a cooperation with Russia regarding a missile system does not diminish our support within NATO. On the contrary, it makes it greater. …there was this necessity and we acted on this necessity.”

On Wednesday, Defense Secretary Jim Mattis met Turkish Minister of Defense Nurettin Canikli at NATO’s gathering of defense ministers, where Pentagon press secretary Dana White issued a statement that seemed designed to acknowledge as many of Turkey’s concerns that the Trump administration could, while maintaining Turkey’s support on the battlefield.

“The secretary thanked the minister for Turkey's continued, critical contributions to global security and the fight to defeat ISIS,” White wrote. “Secretary Mattis acknowledged the threats posed to Turkey, and reiterated that the U.S. will continue to stand with Turkey in its fight against the PKK and all terrorist threats.”

“Secretary Mattis and Minister Canikli agreed to continue their full range of bilateral defense activities and consultations, and to look for ways to further strengthen defense cooperation in the future.”

Yildirim is scheduled to meet with Vice President Pence on Thursday.