The Biden administration is facing mounting pressure to refreeze $6 billion in Iranian assets following Hamas’ attacks on Israel.

The money was included in a U.S.-Iran prisoner swap in September. U.S. officials say the $6 billion can only be used for humanitarian purposes — food, medicine, medical equipment — with U.S. Treasury Department oversight.

The Wall Street Journal reported Monday that Iranian security officials helped Hamas plan and then authorized the assault. The newspaper cited senior members of Hamas and Hezbollah, both Iranian-backed terror groups. 

Twenty Senate Republicans quickly sent a letter to President Joe Biden on Monday mentioning the report and calling for Biden to refreeze the money. 

“To stand by and allow Iran access to these funds as Hamas infiltrates Israel and murders, rapes, and mutilates countless Israelis is unconscionable,” the letter said. “Your administration claims these funds are only available for humanitarian use, but money is fungible, and there is a significant risk they could be used to further efforts by Iran or Hamas against Israel. Moreover, allowing $6 billion to flow into Iran’s economy, even if the purpose is for humanitarian aid, allows the Iranian regime to reallocate even more funds to supporting terrorism.”

Former House Speaker Kevin McCarthy, R-Calif., made the same request while speaking to reporters Monday.

And now, a trio of centrist Senate Democrats have joined Republicans in demanding the money be blocked from Iran.

Sen. Jon Tester, D-Mont., issued a statement Tuesday saying: “As American intelligence officials continue to investigate the terrorist attacks carried out by Hamas, we should review our options to hold Iran accountable for any support they may have provided. At a minimum, we should immediately freeze the $6 billion in Iranian assets and explore other financial tools we have at our disposal.”

Tester is chairman of the Senate Defense Appropriations Subcommittee.

Moderate Sen. Joe Manchin, D-W.Va., has, too, called for the $6 billion to be frozen again.

“I wasn’t supportive of the initial $6 billion transfer,” Manchin said in a statement to multiple media outlets Tuesday. “We should absolutely freeze these Iranian assets while we also consider additional sanctions.”

Earlier Tuesday, Manchin issued a separate statement that said, “Any country or government that is found to be supportive of this terrorist organization [Hamas] should have the most severe sanctions imposed upon them immediately to shut down the support of these terroristic, barbaric actions.” 

The statement did not mention Iran by name.

Meanwhile, Sen. Jacky Rosen, R-Nev., told Politico on Tuesday: “In light of Hamas’s violent and horrific terrorist attack on Israel and Iran’s long-standing support for Hamas, we should freeze these assets.”

Some Republicans have sought to directly link the attacks to the Biden administration’s decision to release the money. 

“We didn’t just invite this aggression, we paid for it,” Sen. Tim Scott, R-S.C., a candidate for president, said Saturday. “Iran is the biggest funder of Hamas. This is the Biden $6 billion ransom payment at work.”

Others Republicans, including former President Donald Trump, have falsely claimed the $6 billion came from U.S. taxpayers. 

Biden administration officials have said that while Iran has a history of funding terrorists, including Hamas, there is no evidence to date it played a direct role in the assault on Israel.

Asked Tuesday about the possibility of refreezing the $6 billion, White House national security adviser Jake Sullivan would only say: “Not a dollar of that money has been spent, and I will leave it at that.”