Russia announced Friday on Telegram it is temporarily limiting exports of enriched uranium to the United States without providing any details as to the restrictions or the duration of the cut-off. 

The move targets a vulnerable U.S. link in the nuclear fuel cycle. Russia is in control of almost half of the world’s capacity to separate the uranium isotopes needed in reactors, and last year supplied more than a quarter of the U.S.’s enriched fuel, according to Bloomberg.

While most deliveries for this year have already been received, this could affect 2025. "There would be some utilities maybe that would be expecting that material and now might not get it,” said Jonathan Hinze, president of a company that tracks uranium-fuel markets.

Russia said the move was a response to a U.S. ban on imports of Russian enriched uranium. President Joe Biden signed that legislation in May, but it allows shipments to continue until 2028 under a system of waivers, according to the outlet. The conclusion being drawn is that the U.S. has allowed its domestic enrichment capacity to languish.

"We don’t have enough enriched uranium here,” Chris Gadomski, head nuclear analyst for BloombergNEF, said in an interview. "They should have been stockpiling enriched uranium in anticipation of this happening.” 

The Biden administration has begun a multibillion-dollar effort to restart the nation’s domestic uranium enrichment capabilities, according to the outlet, but it is still in its formative state.