Sen. Joe Manchin (D-W.Va.) on Tuesday explained the stakes of the U.S. not putting up more support for Ukraine as a congressional package with more aid for the war-torn country remains stalled in the House of Representatives.

Manchin warned that conditions in Ukraine will be extremely dire if the U.S. does not help fund Kyiv’s fight against Russia.

“If it comes through the spring, and we haven’t helped Ukraine, God help us,” Manchin said during a live interview at Axios’ What’s Next Summit in Washington, D.C. “That’ll be the worst atrocity in history that your children and grandchildren will be reading about.”

While a $95 billion foreign assistance package, which includes aid for Ukraine, Israel and Taiwan, was approved by the Senate last month, House Speaker Mike Johnson (R-La.) has so far resisted bringing that bill on the House floor for a vote in fear that the move would anger the right-wing of his conference and, in turn, risk his speakership.

In the meantime, the Biden administration last week announced a $300 million package for Kyiv to “support Ukraine’s immediate air defense, artillery, and anti-tank requirements,” saying this was only possible because of unanticipated contract saving. Still, U.S. officials warned this package would only suffice for a short period of time and have since continued to put pressure on Johnson to help provide a more sustainable solution for Kyiv.

Johnson “has to put politics aside,” White House press secretary Karine Jean-Pierre told reporters Tuesday. “We know what happens when you don’t, when we don’t stop a dictator, when we don’t address tyranny.”

While some Republicans have floated the idea of providing aid to Ukraine on a loan basis, Senate Minority Leader Mitch McConnell (R-Ky.) last week said time is of the essence and the best way forward is approving the bill approved by the upper chamber.

“We’ve got a bill that got 70 votes in the Senate,” McConnell said last week. “Give members of the House of Representatives an opportunity to vote on it. That’s the solution.”

Meanwhile, Defense Secretary Lloyd Austin said Russia has “paid a staggering cost” because of Russian President Vladimir Putin’s “imperial dreams,” as he praised Ukraine for degrading the Kremlin’s capabilities and continuing to fight with resolve as the conflict is now in its third year.

“Now, Ukraine’s troops face harsh conditions and hard fighting. And Ukraine’s civilians endure a constant barrage of Russian missiles and Iranian drones,” Austin said during his opening remarks at the 20th meeting of the Ukraine Defense Contact Group in Germany. “But Ukraine won’t back down. And neither will the United States.”

“So our message today is clear,” he continued. “The United States will not let Ukraine fail. This coalition will not let Ukraine fail. And the free world will not let Ukraine fail.”