The US considers Iran ‘at least complicit’ in Hamas attack on Israel, the State Department said Tuesday, after insisting it had no evidence of Tehran's direct involvement.

Spokesperson Matthew Miller told reporters the Biden administration is now trying to establish if the regime in Iran or elements within the system contributed to the planning of the attack by Hamas militants.

“Iran likely knew that Hamas was planning operations against Israel, but without the precise timing or scope of what occurred,” Miller told journalists at the State Department’s press briefing.

The Islamic Republic has been supporting Hamas for many years. It’s not yet established, however, how far the IRGC was involved in Hamas’ most recent operation.

Ghazi Hamad, a Hamas spokesman, told the BBC that the group had direct backing for the attack on Israel from Iran. A report in Wall Street Journal suggested the same, quoting unnamed sources from Hamas and Hezbollah.

Iran has denied involvement in the operation, which has killed more than 1,200 Israelis. “They say the Islamic Iran was behind this move… they are wrong… Palestinians did it themselves,” said Supreme Leader Ali Khamanei Tuesday.

On numerous occasions before, he has boasted that his regime has had a hand in confrontations against Israel (like the 33-day War with Hezbollah in 2006) and that Iran will keep on helping “any group that fights the Zionist regime.”

The extent of the regime’s involvement in the Hamas attack, if and when it’s established, would likely inform the nature of the response from Israel and the United States. Many in Washington are already pushing for retaliatory measures, including re-freezing the $6 billion of Iran’s old revenue that was unblocked last month to secure the release of five Iranian-Americans held hostage in Tehran.

US Senators have written to President Biden, demanding that access to the money (currently held in a Qatari bank) be denied.

“The State Department should immediately rescind the waivers that allowed Iranian funds converted and moved to more accessible bank accounts,” reads the lawmakers’ letter to Biden, “as well as work with US ally Qatar to immediately freeze the accounts containing these funds.”

The signatories believe that the $6 billion, even if used solely and entirely for humanitarian purposes, would free up other funds in Iran to be used on other, ‘malign’ activities.

Responding to this argument, the State Department Spokesperson said he could confirm that “not a cent” of the $6 billion has been spent at this point. “And we have the ability to freeze it at any time,” Miller concluded.

Hamas’ attack on Israel has enraged those who believe they had warned the Biden administration of the consequences of its lenient approach to the regime in Iran.

“Concessions to the ayatollahs have made them believe America will not stand up for itself or our allies,” Senator Tom Cotton told Fox News Tuesday, “President Biden must reverse his policies that have emboldened Iran and its terrorist proxies.”

It seems to be an attack line the Republicans would not abandon soon.

“Make no mistake— Hamas's genocidal violence was partly enabled by Biden unfreezing billions of dollars to Iran,” Senator Ted Cruz said Tuesday.

Tim Scott, another Republican Senator who is a ranking member of the Senate Committee on Banking, called for a hearing and an investigation into the ‘release of the $6 billion to Iran’.

“We should be signaling strength - not leniency - when it comes to Iran,” Senator Scott said in a statement Tuesday, “that’s why now is the time to pass my Solidify Iran Sanctions Act and send the message that Iran should not expect U.S. sanctions to lapse.”