The chairs of the House Armed Services and Foreign Affairs Committees are pushing the Biden administration to share more defense equipment with Australia and the United Kingdom — America’s two partners in the AUKUS agreement.

In a letter sent to the White House on Tuesday, first reported by Defense News, the two Republican lawmakers argued that the “excluded technologies list” governing what the U.S. can export to either country is still too long. The restrictions, they said, will hinder America’s ability to develop key capabilities to compete with its main rival, China.

“We urge you and your senior leaders to continue to review items included on the ETL and remove as many as possible that do not warrant inclusion in order to unleash AUKUS’ full potential,” wrote Armed Services Chairman Rep. Mike Rogers, R-Ala., and Foreign Affairs Chairman Rep. Mike McCaul, R-Texas.

Under AUKUS, the United States is helping Australia build nuclear-powered submarines, a system so sensitive America had previously only shared it with the U.K. Under the second part of the deal, the three countries are also developing advanced technology, from hypersonic missiles to quantum computing.

One of the main barriers to this effort is the International Traffic in Arms Regulations, or ITAR, a strict set of rules on what weaponry the U.S. exports. The administration loosened these rules for the U.K. and Australia in August, freeing up either country to access 80% of American defense exports without first applying for a license.

What the two lawmakers are now concerned about is the remaining 20%, given how long it can take to get one of those licenses. The U.S. State Department can take more than a month to vet requests, and the application often requires longer prep work beforehand.

“We should move to allow as much sharing of technology as possible,” Deputy Secretary of State Kurt Campbell said in testimony before Congress in September. “We have more work to be done on this.”

The U.S. State Department’s updated rule is still under review, allowing public comment until mid-November. Before the hearing, Campbell gave McCaul a “personal commitment” to shepherd this process through its deadline, said a member of the House Foreign Affairs Committee Republican staff.

The staffer said that the size of the excluded technologies list also depends on how it’s measured: It may be 20% by dollar amount, but it’s 30% by the number of total U.S. licenses.

This list includes weapons and technology restricted by law — such as biological weapons or cluster bombs. But it also includes others only restricted by U.S. policy, such as precision missiles. British and Australian officials often chafe at these delays, since the State Department almost always approves their requests in the end.

Even more, the staff member argued, some of the technology that would be most important to AUKUS is still on that list — adding delays when the U.S. and its allies should be moving faster.

“The Australians have done a full-court press to the Hill, but they’ve also been very vocal to the administration” about loosening the rules, the aide said. Of particular concern to Canberra, the aide continued, are precision weapons, undersea drones and maritime acoustic technology.

The Australian embassy wouldn’t confirm whether those capabilities are of special interest. In a statement, a spokesperson for the embassy said that the government “welcome[ed] continued bipartisan congressional interest in removing barriers to create a seamless trilateral defense industrial base.”

The U.S. State Department could not immediately provide comment.

“We need to make sure we achieve the full potential of the exemption and reap the opportunities it provides for faster, more efficient collaboration between AUKUS partners. Ensuring the scope of the Excluded Technologies list is minimized, where appropriate, and that the regulation itself fully supports our collaboration, will be key to achieving this,” a British official wrote in a statement.

The top U.S., U.K. and Australian defense officials met in London last week to mark AUKUS’ third anniversary and announced the winners of a challenge meant to jumpstart the agreement’s work on advanced technology.

“When the final AUKUS rule is announced in November, we expect to see significant changes,” the lawmakers wrote in their letter.