Lawmakers were united on Thursday in condemning Moscow’s invasion of Ukraine, urging President Joe Biden to immediately impose crippling economic penalties on Russia even as some Republicans accused him of being too timid in his earlier sanctions response.

Lawmakers heaped almost all the blame for the attack at the feet of Russian President Vladimir Putin, who in a televised address late Wednesday night declared he was taking military action to “demilitarize and de-Nazify” Ukraine, which is led by a Jewish president. Already, dozens of Ukrainian troops have been reported killed, according to initial news reports of the Russian military’s air, land and sea-based attacks on key sites and cities around Ukraine.

Speaking in Kentucky, Senate Minority Leader Mitch McConnell urged Biden to “ratchet the sanctions all the way up. Don’t hold any back. Every single available tough sanction should be employed and should be employed now.”

The GOP leader’s comments come as a majority of Americans support tough sanctions on Moscow — and as a majority of Republicans, according to multiple polls, call Putin a strong leader.

Biden, during a midday speech from the White House called Putin “the aggressor,” saying “Putin chose this war and now he and his country will bear the consequences.” The U.S. leader laid out a list of new sanctions he is imposing over the attack, saying those would bring a “severe cost on the Russian economy.” The second batch of U.S. sanctions announced this week target Russian financial institutions and the country’s elite, a group believed to have influence over the Russian president.

“We’re also adding the names to the list of Russian elites and their family members that are sanctioned,” Biden said from the ornate East Room. “These are people who personally gain from the Kremlin’s policies and they should share in the pain.”

Biden described some of his Thursday moves as cutting off Putin’s ability to obtain some technologies crucial to his economy.

“And we’ll strike a blow to their ability to continue to modernize,” he said. “And our military will degrade their aerospace industry … and hurt their ability to build ships, reducing their ability to compete economically. And it will be a major hit to Putin’s long-term strategic ambitions.”

Members of both parties called for a likely sprawling aid package that would fund military aid for Ukraine and also humanitarian assistance. But just how large a package, and how quickly one could be cobbled together and approved by both chambers, was not yet clear. The House and Senate are both on recess and back in session next week.

The sanctions that Biden, along with allies in Berlin, London and Brussels, announced Tuesday took some notable punitive steps against Russia that included ending the certification process of the $11 billion Russian-German Nord Stream 2 natural gas pipeline; sanctioning two Russian financial firms that are used for state-backed development projects and to handle Russian military transactions; and imposing personal sanctions on hundreds of members of Russia’s rubber-stamp parliament, the Duma.

But the heaviest sanctions the United States and Europe could inflict on Russia have been held back on abeyance. Those include sanctions on Russia’s major retail banks, which are relied upon by the Russian general public, and export controls on things such as semiconductors, which would greatly hamper the country’s efforts to modernize and diversify its economy.

But the strongest and most impactful sanctions, according to experts, would be on the export of Russian oil and natural gas. It isn’t clear if Biden and European capitals will choose to deploy that economic “nuclear option,” as doing so would also result in significant pain for European energy importers and badly disrupt the global energy market. 

“Russia has begun an unprovoked, unjustified campaign against Ukraine with a full-on invasion. Civilians are being killed. Ukraine is mobilizing its opposition to the Russian invasion. [We] must provide Ukraine with support to defend itself,” House Intelligence  Chairman Adam Schiff told reporters at a news conference at the Capitol on Thursday. “We also are going to need to, I think, dramatically escalate the sanctions that we place on Russia for this act of naked aggression by the Kremlin dictator. We need to move, I think, to sanction the largest banks in Russia.”

The California Democrat went on to call for sanctions to be imposed that would effectively sever Russian financial institutions from the SWIFT global banking transactions system, freeze assets of Russia’s corrupt oligarchs that are stashed abroad, and ban the export to Moscow of “sophisticated technology for its weapons systems.”

“Vladimir Putin bears full responsibility for Russia’s unjustifiable war against Ukraine,” Senate Armed Services member Elizabeth Warren, D-Mass., one of the most progressive members of her caucus, said in a Thursday statement. “This Russian invasion will cause immense human suffering, including the potential for mass casualties and people displaced from their homes as refugees. Together with our NATO allies and international partners, I support President Biden imposing significant sanctions on Russia’s economy, military, and its corrupt oligarchs as a severe consequence for this unprovoked act of aggression.”

On the other side of the aisle, House Intelligence and Armed Services member Mike Gallagher, R-Wis., who earlier in the week called Biden’s initial sanctions response to Putin’s recognition of two Ukrainian separatist regions “weak and tepid,” on Thursday said “Vladimir Putin is a KGB thug who understands no language except force.”

“He has brought war to Europe because he believes he will secure a quick and decisive victory,” Gallagher said. “Our task is to ensure that he is disappointed, by aiding the Ukrainians who are taking up arms to defend their homeland and imposing economic costs now, not after the inevitable humanitarian disaster.”

And House Minority Leader Kevin McCarthy called Putin’s attack on Ukraine “reckless and evil.”

“Putin’s actions must be met with serious consequences. This act of war is intended to rewrite history and, more concerning, upend the balance of power in Europe. Putin must be held accountable for his actions,” the California Republican said.

At the White House, Biden told reporters it is unlikely the new sanctions from the U.S. and others alone would convince Putin to call off his attack. Still, he vowed to stop the Russian leader.

“America stands up to bullies and we stand up for freedom,” he said. “This is who we are.”

Lindsey McPherson contributed to this report.