The Senate voted on Wednesday in favor of a non-binding motion prohibiting the Biden administration from revoking the Iran Revolutionary Guard Corps’ designation as a foreign terrorist organization.

While the motion, introduced by Republican Sen. James Lankford, is purely symbolic, it is an undoubtedly ominous sign for the U.S. administration as it attempts to break a nearly two-month-long stalemate in talks aimed at returning to the 2015 Iran nuclear deal.

The motion passed by a vote count of 62-33, with a surprisingly high count of 16 Democrats voting in favor. Three of the four Democrats to vote against the 2015 deal — Majority Leader Chuck Schumer and Sens. Ben Cardin and Joe Manchin — were joined by Sens. Richard Blumenthal, Cory Booker, Chris Coons, Catherine Cortez Masto, Kirsten Gillibrand, Maggie Hassan, Mark Kelly, Angus King, Gary Peters, Jacky Rosen, Kyrsten Sinema, Jon Tester, and Ron Wyden.

Sen. Robert Menendez, who voted against the 2015 deal and has been vocally critical of the administration’s ongoing diplomatic efforts, did not vote.

Coons, a close Biden ally, said he supported the motion “to encourage the Biden administration’s negotiations to push for the strongest possible deal” addressing both Iran’s nuclear program and other malign activities, adding he continues to support Biden’s diplomatic efforts in Vienna.

Lankford’s resolution also called for any potential return to the JCPOA to address the “full range of Iran’s destabilizing activities, including the development of the means of delivery for such weapons (and ballistic missiles), support for terrorism and evasion of sanctions by individuals, entities, and vessels in the trade of petroleum products with the People’s Republic of China.” The resolution further prohibits the lifting of existing sanctions on the IRGC.

The IRGC’s removal from the U.S. list of designated terrorist organizations has been the primary sticking point in the Vienna negotiations’ final stages, with the U.S. insisting that it will not take such action unilaterally.

Secretary of State Antony Blinken told the Senate Foreign Relations Committee last month that “the only way I could see [the designation] being lifted is if Iran takes steps necessary to justify the lifting of that designation.

So it knows what it would have to do to see that happen,” adding that “it would require Iran to take certain actions and to sustain them.” He also noted that the designation does not practically do much for the U.S. since there are a myriad of other sanctions on the IRGC