In the wake of recent Hamas attacks on Israel, more than 110 House Representatives have called for a tougher stance against the regime in Iran.

In a letter published Monday night, the lawmakers (63 Democrats and 50 Republicans) urge President Biden to hold the Islamic Republic accountable for its ongoing financial support of Hamas.

“We urge the Administration to take all necessary steps to cut off Iranian funding sources,” the letter reads. “This includes maximum enforcement of all US sanctions and taking any and all steps to end Iran’s oil trade to China, which currently brings in $150 million per day in revenue.”

This House initiative is the latest in a long line of Congressional efforts in the past few weeks, aiming to force the Biden administration to exert more pressure on Iran, restricting the regime’s access to funds, in particular.

Top Iranian officials, including the Supreme Leader Ali Khamenei, have praised Hamas for the brutal attack on Israel that killed more than 1,300 civilians. On Tuesday, Khamenei dismissed those deaths, saying that Israeli civilians have weapons and are considered combatants.

In a separate initiative Tuesday, a group of Senate Republicans demanded once more that the administration refreeze the $6 billion in Iranian oil revenue that was released as part of a deal to free five hostages from Tehran.

“We know that Iran bankrolls Hamas,” said Senator Balckburn, leading the group. “It is perplexing why this administration refuses to issue a formal decision to freeze the $6 billion. We need to ensure that not another dollar goes to Iran.”

Many US lawmakers have visibly lost patience with Biden over what they see as unwarranted leniency towards the Islamic Republic, which seems to have led to a replenishment of the regime’s coffers after a period of hardship brought about by President Trump’s ‘maximum pressure’.

Senator George Marshall, one of the more vocal members of the Senatorial group who demanded the ‘refreeze’ on Tuesday, claimed that under Biden, Iran's currency reserves have gone “from $6 billion to $60 billion” because the regime has been allowed to sell “a billion dollars’ worth of oil every week to China.”

“Iran has played Joe Biden like a cheap fiddle,” said Senator Marshal. “Joe Biden has ignored sanctions for two years now, and now he’s lifting those sanctions.”

On October 18, the UN ballistic missile sanctions will expire under the terms of the Joint Comprehensive Plan of Action (JCPOA). As things stands, President Biden will arrive in Israel on the same day that he allows UN sanctions to be lifted on Iran’s capability to purchase and supply missiles.

“This cannot be allowed to happen,” write the Representative in their letter to Biden. “We urge your Administration to work with our European allies to immediately implement snapback sanctions on Iran at the UN Security Council.”

President Biden in Israel is expected to urge Netanyahu to allow humanitarian aid for Gaza while exploring all routes that may help retrieve the American hostages taken by Hamas during their incursion into Israel.

More than 1,500 were killed in the attack, including soldiers. Neearly twice that number have been killed so far by Israeli airstrikes on Gaza. Many fear that a looming Israeli ground invasion would dramatically increase the number of casualties and bring into the war other regional actors like Hezbollah.

Hezbollah has reportedly stockpiled tens of thousands of rockets since its last war with Israel in 2006. The group has been funded by the Islamic Republic, which sees it as an strategic ally in Israel's backyard.

Critics of the Biden administration believe its reluctance to pressure Iran in the hope of a nuclear deal has emboldened not only the regime but its proxies across the region.

Those most vocal, like Senator Ted Cruz, are going beyond the usual critique and accuse the administration of letting in ‘compromised’ individuals who have then influenced foreign policy.

On Tuesday, Senator Cruz once more addressed this issue in an interview with Fox News.

“Rob Malley, Biden’s Special Envoy to Iran, appointed Iranian operatives to key positions in the US government,” he said. “Democrats have yet to allow the Senate Foreign Relations Committee to hold a hearing about this. This is disgraceful.”