Republican senators introduced a bill Friday that would make any deal with Iran over its nuclear program subject to Senate approval as the GOP looks to head off one of President Biden’s top foreign policy priorities. 

The effort is being led by Sen. Ron Johnson (R-Wis.), who has been a vocal critic of Biden’s efforts to get Washington and Tehran back into compliance with the 2015 nuclear deal. The bill would deem any deal made with Tehran a treaty, which requires the Senate to sign off with a two-thirds majority before it goes into effect.

“It’s clear the Biden administration is in the business of appeasing adversaries like Russia, state sponsors of terrorism like Iran, and Iran’s terrorist proxies like Hamas. Instead of addressing the threats these actors pose, the administration will coddle the Iranian regime and ignore its malign activity throughout the region. Any potential agreement with Iran involves risks that affect our entire nation,” Johnson said in a statement.

“It is critical to the security of America and to world peace that any deal Biden negotiates with Iran be deemed a treaty requiring approval by the U.S. Senate.”

The bill’s introduction comes as the administration conducts indirect talks with Iran through European intermediaries in Vienna.

The White House has touted the talks as necessary to bring safety and stability back to the Middle East, while Republicans have said a return to the deal would not stop Iran’s path to a nuclear weapon and would not address what they say are its malign activities in the region. 

Pressure on Biden to take a tough tact with Iran only increased as Tehran sends two warships across the Atlantic Ocean, reportedly to deliver weapons to Venezuela, a move that would be seen as highly provocative by lawmakers of both parties. 

“The Iranian regime presents a significant and enduring challenge to United States’ national security interests. While negotiators gather in Vienna, Iran continues to develop ballistic missiles, attacks American troops and diplomats in Iraq, funds Hamas’ attacks against Israel, facilitates Houthi aggression in Yemen, and enables the Assad regime’s continued atrocities in Syria,” said Sen. Jim Risch (R-Idaho), who is leading the bill with Johnson and is the top Republican on the Senate Foreign Relations Committee.