Hours after a heated closed-door confrontation with Senate Republicans, President Donald Trump on Wednesday decried the Senate for voting to end the war with Iran, saying that he believes the timing of the measure could interrupt ongoing negotiations and give Iran more leverage.

“We’re doing great in our negotiations with Iran,” Trump said when asked by TIME in the Oval Office whether the Senate vote had complicated talks. “Right in the middle of one of the key things, which we’re going to get anyway, we have breaking news: The Senate has voted that they’d like Trump to stop the war.”

“So Iran sees that,” Trump continued, “They go, ‘What’s that all about?’ No, you know it’s meaningless.”

Trump’s comments followed an increasingly bitter meeting with Senate Republicans that erupted into a shouting match behind closed doors on Wednesday, as the President angrily confronted members of his own party over the Senate’s vote rebuking his handling of the war in Iran. The confrontation unfolded during a private lunch meeting at the Capitol, where Trump had originally been expected to pressure senators to advance his election legislation, known as the SAVE America Act. Instead, according to senators present, the discussion was dominated by a bipartisan vote a day earlier directing the President to end military operations against Iran or seek congressional authorization to continue them—a largely symbolic measure but one that nonetheless marked the first time the Senate had formally approved a war powers resolution related to the conflict.

The episode laid bare a widening struggle between Trump and Senate Republicans over the foreign policy issue as the party heads into the midterm elections. Senators described the President arriving visibly angry and launching into an extended denunciation of the four Republicans who joined Democrats in supporting the Iran resolution: Senators Lisa Murkowski of Alaska, Susan Collins of Maine, Rand Paul of Kentucky, and Bill Cassidy of Louisiana. 

Cassidy, who lost his primary this year after Trump endorsed a challenger, later recounted standing up to defend his vote, setting off a heated exchange with the President. “I stood and said, ‘You have not told the American people what’s going on,’” Cassidy told reporters afterward. “This was supposed to last four weeks, it’s lasted four months. Our original objectives have not been achieved.”

Cassidy said he and the President “went back and forth” and that he “matched his tone and volume” during the exchange before attempting to lower tensions. “I am voting for war powers until I get a briefing,” he said. “I did not want to be bullied.”

The Senate War Powers resolution carried little practical effect because it cannot, by itself, force the President to withdraw forces. But its adoption represented a significant bipartisan statement that many lawmakers believe Congress should play a larger role in decisions about an extended military conflict.

Shortly after Trump’s comments in the Oval Office dismissing the War Powers vote, Senator Lindsey Graham of South Carolina, a vocal supporter of military action against Iran, posted on social media that “The president’s concern about Iran being emboldened by this vote in the middle of negotiations to end this war is not unwarranted” and that “votes like this have the unintended consequence of extending the conflict.” He called for a re-vote on the War Powers Resolution.

Trump’s comments reflected a central argument advanced by the White House throughout the conflict: that public displays of division inside the President’s party can weaken U.S. leverage abroad. But Democrats and the four Republicans who voted with them have countered that congressional oversight is especially important in a military operation that has expanded well beyond its original timeline and objectives. Many of Trump’s allies have also raised questions about the Administration’s proposed settlement with Iran, even as they stopped short of backing congressional efforts to restrain him.

“Democrats, they want to lose the war because they're stupid,” Trump said Wednesday. “That's why we call them Dum-ocrats, you know. I no longer use the E. I use—I've changed the E into a U. We call them Dum-ocrats. They're dumb.”

The Senate GOP lunch was intended to smooth tensions over the SAVE America Act, Trump’s priority legislation that would require proof of citizenship for voter registration and impose other election-related restrictions. He has repeatedly urged Senate Republicans to weaken or eliminate the filibuster to advance the measure despite insistence from Senate leaders that the votes do not exist.

Just before the lunch meeting, Trump abruptly canceled the signing of a landmark bipartisan housing bill, and announced he wouldn’t sign the bill until Congress passed the SAVE America Act. The housing bill can still pass without Trump’s signature.

Senator John Thune of South Dakota, the majority leader, has argued that the SAVE America Act doesn’t have the votes and cannot overcome Senate procedural hurdles. On Tuesday, he bluntly said that passage is “just not realistic.”

Earlier Wednesday, as he was leaving the contentious lunch, Trump told reporters that, “We like our leader” before adding: “I don’t like a few people, but that’s ok.”