An Oval Office meeting yesterday with Turkey's President Recep Tayyip Erdoğan took a dark turn when Erdoğan pulled out his iPad and made the group watch a propaganda video that depicted the leader of the primarily-Kurdish Syrian Democratic Forces as a terrorist, according to three sources familiar with the meeting.

Why it matters: The meeting hosted by President Trump included five Republican U.S. senators who've been among the most vocal critics of Turkey's recent invasion of Syria and attacks on the U.S.'s Kurdish allies in the fight against ISIS.

Erdoğan apparently thought he could sway these senators by forcing them to watch a clunky propaganda film.

The senators in the meeting took turns pushing back on Erdoğan, while Trump sat back and watched, intervening occasionally to play traffic cop.

The meeting comes as Erdoğan is trying to avoid sanctions over the purchase of a Russian missile defense system.

Erdoğan's video "was unpersuasive," according to a source who was in the room. It depicted members of the YPG (the U.S.-allied People's Protection Units) and the PKK (the Kurdistan Workers' Party, which the State Department has designated as a terrorist group).

After the film concluded, according to the source, Sen. Lindsey Graham asked Erdoğan: "Well, do you want me to go get the Kurds to make one about what you've done?"

Erdoğan got into a heated back-and-forth with Graham over Turkey's recent invasion of Syria, according to four sources familiar with the meeting. A source in the room said Erdoğan took exception to Graham using the word "invasion" and that Graham also rebutted Erdoğan when he claimed that Turkey had fought ISIS.

Turkish officials could not immediately be reached for comment.

In a phone interview last night, Graham confirmed he clashed with Erdoğan in the Oval. "The Turkish narrative that they have done more to destroy ISIS, I rejected forcefully, and I let Turkey know that 10,000 SDF fighters, mostly Kurds, suffered, died or injured, in the fight against ISIS, and America will not forget that and will not abandon them."

Reality check: Trump has said the opposite about the Kurds. He said it's not in America's interests to defend them, and that the U.S. should withdraw from Syria so they can fight it out with the Turks. Trump later reversed course, saying he'd leave some troops in Syria, but only to "keep the oil."

Behind the scenes: A senior administration official said they invited these senators because they have voiced concerns about Turkey's purchase of Russian weapons and invasion of Syria. "It shows Erdoğan that they're serious about sanctions, and Trump doesn't have to be the bad guy," the official said. Another senior official said the president believes "full and frank" engagement with Erdoğan is important.

Sen. Ted Cruz said in a statement that he "made clear to President Erdoğan that so long as Turkey continues to procure or deploy the S-400 air defense system from Russia, the U.S. will not sell F-35 fighter jets to Turkey." All the senators in the room, including Joni Ernst and Senate Foreign Relations Chair Jim Risch, were unified on the S-400 point.

Sen. Rick Scott pressed Erdoğan on "why Turkey should enjoy the protections of NATO when they're cozying up to Russia," according to another source familiar with the meeting.

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