(NEXSTAR) – Nuclear security experts are sounding the alarm over China and Russia’s rising nuclear programs.

On Tuesday, at a Senate hearing, they warned the U.S. could be underprepared without new investments.

Experts are urging Congress to quickly address what they call growing threats from the two countries.

“The doomsday clock tool is now set to 100 seconds to midnight – in contrast, at the end of the Cold War,  the clock setting was 17 minutes to midnight,” said Madelyn Creedon, research professor at George Washington University’s Elliott School of International Affairs.

The panel of experts warned senators that both China and Russia have dramatically increased their nuclear capabilities.

“The world is very different now,” said Franklin Miller, a foreign policy and nuclear security expert with The Scowcroft Group. Miller, who also served as a special assistant to former President George W. Bush, said that as Russia and China continue a more aggressive global strategy, the U.S. must proactively prepare for how to respond if those two countries unite.

“Our goal must be a secure and effective deterrent,” Miller said. 

The experts emphasized that creating such a deterrent would require the U.S. to modernize its technology, recruit more talent and pursue updated treaties with both countries.

“It is urgently needed,” said Rose Gottemoeller, who served as deputy secretary general of NATO from 2016 to 2019. “Going forward I think we should be looking at all different instruments.”

Michigan democratic senator Gary Peters says he’s also concerned about what happens if China or Russia develop autonomous nuclear weapons.

“Because clearly this is coming – this is not if, this is when,” Peters said. “If we go that route we have to make sure that we can respond.”

Oklahoma Republican Sen. Jim Inhofe says a bipartisan group of lawmakers are working together right now to ensure the country’s defenses do not fall behind.

“It’s clear we are not prepared for this reality,” Inhofe said.