President Joe Biden’s bid to revive the Iran nuclear deal flunked its first test in the U.S. Senate, Politico reported.

Senators voted late Wednesday to endorse a Republican-led measure stating that any nuclear agreement with Tehran should also address what they claimed Iran’s support for terrorism in the region, and that the U.S. should not lift sanctions on a branch of the Iranian military, the Islamic Revolution Guard Corps (IRGC).

Former U.S. President Donald Trump blacklisted the IRGC to make a return to the nuclear deal, which he abandoned in May 2018, difficult.

16 Democrats voted with almost all Republicans to approve Sen. James Lankford’s (R-Okla.) motion.

While the measure itself was non-binding, the vote was hailed as a modest victory for Republicans who have pushed the Biden administration to walk away from the talks in Vienna.

Lawmakers from both parties said it was a warning shot to Biden’s negotiating team, who have all but acknowledged in private that an agreement that goes beyond curtailing Iran’s nuclear program is no longer possible, according to multiple people familiar with classified Hill briefings on the subject.

 “We want a longer and stronger deal,” Sen. Cory Booker (D-N.J.) said when asked why he supported the measure. “[I want] the best deal possible that secures the region and prevents Iran from having a nuclear weapon.”

Contrary to claims by certain U.S. Congresspersons, Iran has said it will not seek nuclear weapons with or without a nuclear deal.  The Leader of the Islamic Revolution Ayatollah Ali Khamenei has also banned production, stockpiling and use of weapons of mass destruction (WMDs) including nuclear arms. 

Sen. Chris Murphy (D-Conn.), who spoke on the Senate floor against the measure, suggested it could undermine the Biden administration’s efforts and said it would be an endorsement of the Donald Trump-era approach to Iran.

“To deny this administration the ability to enter into a nuclear agreement isn’t just folly, it’s downright dangerous…. We should not endorse four more years of this failed Iran policy,” Murphy said.

Senate Majority Whip Dick Durbin (D-Ill.) downplayed the vote and said he expects at least half of the Democrats who supported the Lankford motion would ultimately side with the Biden administration on a nuclear deal.

“It was a non-binding vote. It’s a political year,” Durbin said.

A State Department spokesperson reiterated that Biden is seeking a full return to the 2015 agreement and said “nothing in a nuclear deal would diminish our resolve to continue combatting” Iran’s ballistic missile program and its policy in the region.

“If and when we conclude a deal on mutual return to full implementation of the [2015 deal], we will look forward to defending it in detail, and we are confident that it will have support in Congress and with the American people,” the spokesperson added.

Most Democrats, even those who opposed the initial deal, criticized Trump for pulling out of the agreement in 2018 and implementing a so-called maximum pressure campaign of sanctions and other punitive measures against Iran. Democrats say Trump’s policy failed, pushing Iran much closer to achieving full nuclear capabilities.

Iran has demanded that the U.S. scrap the IRGC’s designation as a foreign terrorist organization as part of an eventual nuclear agreement. Allies of the Biden team have argued that the designation itself is largely symbolic. But dozens of Democrats, particularly in the House, have urged the Biden administration to resist delisting the IRGC.