Standing next to Turkish President Recep Tayyip Erdogan at the White House this week, President Trump sounded upbeat about the prospects of improving the souring relationship between the United States and Turkey.

But inside an unusual Oval Office gathering convened with five of Erdogan’s most vocal Republican critics from the Senate, the tenor was markedly different.

One GOP senator after another took turns confronting the Turkish president, according to those present, as Republican lawmakers challenged Erdogan on Turkey’s violent incursion into northern Syria last month and his country’s purchase of the S-400 missile defense system from Russia.

Throughout the discussion Wednesday, Trump largely hung back, allowing the senators to project a unified stance of condemnation that has been widespread on Capitol Hill but which has often run counter to Trump’s own warm attitude toward Erdogan.

And Trump’s efforts to open lines of communication between Erdogan and his biggest congressional critics led to little in the way of tangible results, senators said — raising scrutiny of Trump’s efforts to coax a deal with Erdogan as the U.S. president faces bipartisan pressure for a tougher posture toward Turkey.

“I don’t think you can say at the end of the meeting, ‘Oh, something changed,’ ” Sen. Rick Scott (R-Fla.), one of five Republican senators who took part in the Oval Office gathering, said Thursday. But “I don’t think there’s any question that Erdogan knows exactly where at least the five senators there are.”

Congress has registered broad disapproval of Turkey’s recent actions, most notably its invasion into northern Syria that was precipitated by Trump’s decision to order most U.S. troops withdrawn from the region. The House overwhelmingly approved new sanctions against Turkey last month in a bid to punish the NATO ally for its military offensive against U.S.-allied Kurdish fighters, with just 15 dissenters.

The Senate has proposed similar sanctions targeting Turkey, although they have been on hold pending Erdogan’s visit to the White House this week. Senators have also warned that Erdogan faces imminent sanctions for Turkey’s purchase of the S-400 missile defense system, although Trump has delayed imposing the sanctions, which are required under law.

“There was no agreement on the Kurd issue . . . no agreement obviously on the S-400,” said Sen. Joni Ernst (R-Iowa), another senator present for the contentious talks with Erdogan. “No tangible result. However, I would say the fact that we were able to sit down and have that meeting was very important.”

In the end, Trump’s hosting of Erdogan produced little clarity on how the differences between the countries will get resolved, as Trump declared progress while providing few details in public.

Trump touted “tremendous progress” toward a potential $100 billion trade agreement that would more than quadruple trade between the two countries. He said a tentative cease-fire was holding in northern Syria and was optimistic on the prospects for a solution on Turkey’s S-400 purchase.

At a separate lunch of 10 GOP senators on Thursday, Trump said the administration was continuing to push Turkey to purchase the U.S.-made Patriot missile defense system rather than the S-400, according to a senator in attendance and another person briefed on the meeting. He blamed his predecessor, President Barack Obama, who Trump said should have sold the Patriot system to Turkey while he was in office.

To Trump’s critics in Congress, the president’s efforts to play mediator rang hollow.

“The president was trying to check a box,” said Sen. Chris Murphy (D-Conn.), a member of the Senate Foreign Relations Committee, arguing that Trump used Republican senators to project toughness toward the Turkish leader “without actually doing it himself.”

Murphy added: “Erdogan knows all he had to do was to sit through a handful of uncomfortable minutes and then he goes back to the status quo, which is getting almost anything he wants from this president. I thought it was weak and feckless and to me, a tell that the president doesn’t have any interest in getting tough with Turkey.”

Indeed, the GOP senators’ confrontational tone toward Erdogan — and the Turkish leader’s defensive posture, according to the senators who attended — was a marked shift from the warm demeanor Trump projected during his public appearances with Erdogan.

Sen. Ted Cruz (R-Tex.), who was traveling abroad when the Turkish offensive in northern Syria began, relayed concerns he heard at the time that the United States appeared willing to abandon an ally. Ernst, a combat veteran, noted that she had served with Kurdish allies in Iraq.

Senate Foreign Relations Committee Chairman James E. Risch (R-Idaho) warned that Turkey’s purchase of the Russian missile defense system would be fundamentally incompatible with U.S. interests. And Scott asked Erdogan why Turkey should enjoy the protections afforded through its membership in the NATO alliance when he was willing to ally with Russia, according to attendees and others briefed on the discussion.

Erdogan responded by pressing the senators repeatedly on whether they wanted the Turkish leader to sever ties with Russia altogether. The senators said that was not the case but rather that Turkey should not implement the S-400 system and avoid mandatory sanctions from the United States.

“We should be moving forward with (sanctions), unless President Erdogan changes his direction,” Ernst said. “However, they are a NATO ally, and what I hate is that if we are imposing sanctions, we are pushing them further away from us and into the arms of Russia. And I hate that thought.”

Erdogan also played a three-minute video that senators described as a propaganda film that purportedly showed terrorist attacks perpetrated by the Kurdistan Workers’ Party (PKK), a Kurdish group that the Turkish leader has deemed a threat to his citizens. No one appeared to find the video, first reported by Axios, persuasive.

“What I told him is, I’m not here to retry the past,” Sen. Lindsey O. Graham (R-S.C.) said Thursday. “I acknowledge you’ve got legitimate national security interests about armed elements on your border. But you want me to get the Kurds to play a video about what your forces have done?”

Risch said Thursday that he is holding off on moving sanctions legislation through his committee while negotiations over the S-400 are pending. But he signaled that action could be imminent, saying a markup could come in the “next few weeks.”

The meeting, Risch said, was “very therapeutic.”

“President Erdogan isn’t completely there yet, but it’s a give-and-take proposition,” Risch said. “He is very clearly aware of the decisions that he has to make, and the repercussions for those decisions.”