Senators on Wednesday blocked a Republican push to tie Iran's support of terrorism to a final deal on the country's nuclear program.

Senators voted 45-54 on the amendment from Sen. John BarrassoJohn Anthony BarrassoNo better time to modernize America's energy infrastructure EPA's Wheeler grilled by Democrats over environmental rollbacks amid COVID-19 The Hill's Coronavirus Report: Former Rep. Harman says Russia is trying to exploit America; Mylan's Heather Bresch says US should make strategic reserve in medicines; Trump unveils leaders of 'Warp Speed' MORE (R-Wyo.), which would have required President Obama to certify as part of a diplomatic deal that Iran hasn't carried out or directly supported an act of terror against the United States or a U.S. citizen.

Republican Sens. Lamar AlexanderAndrew (Lamar) Lamar AlexanderSoured on Fox, Trump may be seeking new propaganda outlet Senators weigh traveling amid coronavirus ahead of Memorial Day McConnell gives two vulnerable senators a boost with vote on outdoor recreation bill MORE (Tenn.), Dan CoatsDaniel (Dan) Ray CoatsGerman lawmaker, US ambassador to Germany trade jabs Intelligence agencies have hired outside consultants to improve communication with Trump: report Senate confirms Ratcliffe to be Trump's spy chief MORE (Ind.), Bob CorkerRobert (Bob) Phillips CorkerRomney is only GOP senator not on new White House coronavirus task force McConnell, Romney vie for influence over Trump's trial RNC says ex-Trump ambassador nominee's efforts 'to link future contributions to an official action' were 'inappropriate' MORE (Tenn.), David Perdue (Ga.), Jeff FlakeJeffrey (Jeff) Lane Flake'Never Trump' Republicans: Fringe, or force to be reckoned with? The Memo: Can the Never Trumpers succeed? Former GOP Sen. Jeff Flake says he will not vote for Trump MORE (Ariz.), Lindsey GrahamLindsey Olin GrahamThe Hill's Morning Report - Presented by Facebook - US virus deaths exceed 100,000; Pelosi pulls FISA bill Frustration builds in key committee ahead of Graham subpoena vote  GOP senators urge Trump not to restrict guest worker visas MORE (S.C.), Orrin HatchOrrin Grant HatchBottom line Bottom line Bottom line MORE (Utah) and John McCainJohn Sidney McCainHow Obama just endorsed Trump Former Texas Rep. Sam Johnson dies at 89 Trump's needless nastiness and cruelty will catch up with him MORE (Ariz.) voted with Democrats against the amendment.

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Sen. Ben CardinBenjamin (Ben) Louis CardinLawmakers urge Trump to cancel DC's July 4 event: 'Impossible to put on safely' This week: Surveillance fight sets early test for House's proxy voting GOP faces internal conflicts on fifth coronavirus bill MORE (D-Md.) said ahead of the vote that Barrasso's amendment was a "poison pill" for the legislation. The White House had warned it would not accept such a provision, and it was stripped from an earlier version of the legislation.

The Maryland Democrat, who is ranking member of Foreign Relations Committee, said the problem with the amendment, and those like it, is that it goes "beyond the terms of the nuclear agreement.

Barrasso countered that it was "important" to reinsert the terrorism measure, which was removed as part of an agreement between Cardin and Corker.

"I think it's very important that the American people get regular certifications from the president on this important point," he said. "Congress and the American people need to know if Iran is directly supporting acts of terrorism against our country and our people."

Roughly a dozen Republicans, including Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellMcConnell urges people to wear masks: 'There's no stigma' Frustration builds in key committee ahead of Graham subpoena vote  Lack of child care poses major hurdle as businesses reopen MORE (Ky.), presidential hopeful Sen. Marco RubioMarco Antonio RubioThe Memo: Trump's Scarborough tweets unsettle his allies House passes bill that would sanction Chinese officials over Xinjiang camps Rubio: Coronavirus conspiracy theories could be used in foreign election misinformation campaigns MORE (Fla.) and Corker, huddled on the floor during the vote.

The senators at one point realized they were being watched by reporters, with Sen. John ThuneJohn Randolph ThuneFrustration builds in key committee ahead of Graham subpoena vote  The Hill's Morning Report - Presented by Facebook - US death toll nears 100,000 as country grapples with reopening GOP faces internal conflicts on fifth coronavirus bill MORE (R-S.D.) turning around and gesturing to the press gallery.

It's unclear what the meeting on the floor was about. Sen. James Risch (R-Idaho) told reporters after the vote, "We were talking about the details of the bill; that was pretty obvious wasn't it?"

He added, "It was about various aspects of the bill. ... We all have questions about it."

Asked if senators were trying to convince Rubio to stand down on his amendment that would link Israel's right to exist to the bill, Risch said, "There was nobody trying to get anybody to do anything."

Cardin blocked Rubio from bringing up his amendment.

Rubio didn't respond to questions from reporters.