The Biden administration is considering banning imports of enriched Russian uranium using executive authority as congressional efforts to block the Kremlin’s shipments of the reactor fuel stall, people familiar with the matter said.

Officials from the White House National Security Council, the Department of Energy and other corners of the administration have been in talks on limiting Russian uranium imports, including a ban that includes waivers similar to legislation the easily passed the House last year, the people said.

The Energy Department referred comment to the National Security Council, which didn’t immediately respond to a request for comment.

To be sure, no decisions have been made on the issue and the administration — and the nuclear industry — still prefer the matter to be handled by Congress because undoing a law is harder than overturning actions done using executive power, the people said.

Russia provided almost a quarter of the enriched uranium used to fuel America’s fleet of more than 90 commercial reactors, making it the No. 1 foreign supplier, according to Energy Department data. Those sales provide an estimated $1-billion a year to Russia, and the White House has said dependence on Russian sources of uranium “creates risk to the US economy.” At the same time, replacing that supply could be a challenge and is poised to raise the costs of enriched uranium by as much as 20%.

Adding urgency to the issue is that $2.7-billion made available by Congress earlier this year to stand up a domestic uranium industry is contingent on limits or a prohibition on enriched Russian uranium being put in place either by law or administrative action.

House legislation passed legislation by voice vote in December would ban enriched Russian uranium imports while allowing the import of the reactor fuel until 2028 through waivers designed to give utilities time to line up alternative supplies. But an effort by the Senate to quickly follow suit was blocked over unrelated matters by Texas Republican Senator Ted Cruz.

Because of procedural rules, the next best potential legislative vehicle to attach the uranium ban in the Senate to is must-pass legislation needed to reauthorize the Federal Aviation Administration, which is slated for the Senate floor this week. But Senator Maria Cantwell, a Washington Democrat who chairs the Senate transportation committee with jurisdiction over the bill, said earlier a uranium ban was unlikely to be attached to the legislation.

“At the leadership level they don’t want a lot of stuff on there,” Cantwell said in a Thursday interview.

Further complicating matters, the top Republican on the committee is Cruz, the Senator who blocked the House-passed bill from proceeding.

The White House, which has said the creation of a domestic nuclear fuel enrichment supply chain is a national security priority, has previously called for a long-term ban to be coupled with the billions of dollars now approved by Congress for domestic enrichment capabilities.

Energy Secretary Jennifer Granholm, when asked about the issue while testifying before a House hearing last month said executive action “is possible” but Congressional action was preferable.

“We’re concerned about the enduring nature of it,” she said. “If Congress acts on it, it obviously solidifies it more concretely. And hopefully we can see that happen.”