WASHINGTON (AP) — President Joe Biden said Friday that the apparent death of Russian anti-corruption activist Alexei Navalny brings new urgency to the need for Congress to approve tens of billions of dollars for Ukraine to stave off Moscow's invasion.

Speaking at the White House, Biden said that no matter the cause, he holds Russian President Vladimir Putin responsible for Navalny's death. He added, “I hope to God it helps” push U.S. lawmakers to send more aid to Ukraine.

Biden said that “history is watching” lawmakers in the House, which hasn't moved to take up a Senate-passed bill that would send funds and armaments to Ukraine, whose troops U.S. officials say are running out of critical munitions on the battlefield.

“The failure to support Ukraine at this critical moment will never be forgotten,” Biden said. “And the clock is ticking. This has to happen. We have to help now.”

Biden said the U.S. had not confirmed Navalny's death in a Russian prison above the Arctic Circle, but that he had no reason to doubt it either.

The president sharply criticized House Republicans for letting the chamber enter a two-week recess without moving on the Ukraine funding.

“What are they thinking — my God,” Biden said. “This is bizarre and it’s just reinforcing all of the concern — I won’t say panic but real concern — about the United States being a responsible ally.”

Republican Speaker Mike Johnson earlier this week said the House won't be “rushed” to pass the aid, but on Friday he said Putin was “a vicious dictator and the world knows he is likely directly responsible for the sudden death of his most prominent political opponent.”

"We must be clear that Putin will be met with united opposition,” Johnson, R-La., said in a statement. “As Congress debates the best path forward to support Ukraine, the United States, and our partners, must be using every means available to cut off Putin’s ability to fund his unprovoked war in Ukraine and aggression against the Baltic states.”

Lawmakers who have pushed for the Ukraine aid blamed the Republicans who have sided with former President Donald Trump as he has urged its defeat.

Democratic Leader Hakeem Jeffries, D-N.Y., said, “Shame on the pro-Putin MAGA extremists who continue to block bipartisan national security legislation in the House,” referencing Trump's “Make American Great Again” slogan.

North Carolina Sen. Thom Tillis, one of 22 Republicans who voted for the Senate-passed Ukraine aid package, said that Navalny laid down his life fighting for a country he loved and that “Putin is a murderous, paranoid dictator.”

“History will not be kind to those in America who make apologies for Putin and praise Russian autocracy,” Tillis posted on X, formerly Twitter. “Nor will history be kind to America’s leaders who stay silent because they fear backlash from online pundits.”

Biden, eyeing a likely general election rematch against Trump this November, said American presidents from Harry Truman on are “rolling over in their graves” hearing Trump's comments suggesting that the U.S. might not defend its NATO allies who fail to meet their defense spending targets if attacked.

“As long as I'm president, America stands by its sacred commitment to our allies," Biden said.