The Pentagon is reviewing America’s role in a historic, multibillion-dollar pact among Washington, the United Kingdom and Australia to ward off China’s growing influence.

The widely supported deal calls on the three countries to jointly develop hypersonic weapons and nuclear-powered submarines, a unique security partnership that could strengthen seapower gaps in the Pacific and produce transformative new weapons.

Pentagon policy chief Elbridge Colby — who has expressed skepticism about the program’s worth — is running the review, according to two defense officials, granted anonymity to discuss internal policy talks.

“This is an opportunity for the [Defense Department] to ensure the effort is in alignment with the Trump administration’s priorities,” one of the officials said.

The Biden administration inked the deal, known as AUKUS, four years ago. The people did not say how the Trump administration could tweak the massive package of cooperative efforts or when officials would make a decision. But the agreement appears to have the backing of numerous lawmakers and Secretary of State Marco Rubio, who expressed support for it during his confirmation hearing.

The Defense Department did not respond to a request for comment. The Financial Times first reported the review.

Such assessments aren’t entirely unusual. British Prime Minister Keir Starmer initiated a review of AUKUS after his election last year.

A U.K. government spokesperson, granted anonymity to discuss the situation, said the review was “understandable” and that London would continue to work closely with the U.S. and Australia on the deal.

But the development was met with frustration from congressional Democrats, especially on the Eastern Seaboard, which houses some of America’s largest shipyards. Australia has committed to investing $3 billion in modernizing U.S. shipyards that produce nuclear-powered submarines, a massive influx in cash that would benefit American industry and bulk up its ability to produce submarines.

New Hampshire Sen. Jeanne Shaheen, the top Democrat on the Senate Foreign Relations Committee, said news of the review “will be met with cheers in Beijing.”

She added that scrapping the partnership would “further tarnish America’s reputation and raise more questions among our closest defense partners about our reliability.”

Colby has challenged major parts of the AUKUS deal, including a plan for the U.S. to sell three Virginia-class submarines to Australia, citing the need for the U.S. to maintain a robust undersea presence in the Pacific. The Virginia sales would come in three-year intervals starting in 2032 and would replace the retiring Collins-class submarines in the Australian arsenal.

But Colby appeared more open to the project during his Senate confirmation hearing in March. “It should be the policy of the United States government to do everything we can to make this work,” he said.

Colby did note he was concerned that selling submarines to Australia, or using U.S. shipyards to help build them, could put the U.S. Navy in “a weaker position” since they weren’t going to American submarine development.

The agreement would also mean closer cooperation among the three nations in building quantum computers and hypersonic weapons. And it has largely moved forward without controversy. Australian Deputy Prime Minister Richard Marles met with Defense Secretary Pete Hegseth at the Pentagon in February and pledged the first $500 million of a $3 billion investment.

President Donald Trump “is very aware, supportive of AUKUS, recognizes the importance of the defense industrial base,” Hegseth said at the meeting.

The three nations already have poured millions into training to operate nuclear-powered vessels. Australia has funneled even more into expanding its base in Perth on the country’s western edge.

Connecticut Rep. Joe Courtney, the top Democrat on the House Armed Services seapower subcommittee, questioned why the administration would launch the review when so much is underway.

“To walk away from all the sunk costs invested by our two closest allies, Australia and the United Kingdom, will have far-reaching ramifications on our trustworthiness on the global stage,” he said. “It is a direct contradiction to the administration’s ‘America first, but not alone’ goal of countering aggression from China, Russia and other adversaries.”

Joe Gould and Esther Webber contributed to this report.