Belarus suspended an agreement with the U.S. to get rid of its highly enriched uranium stockpile after Washington imposed new economic sanctions on the former Soviet republic.
The pact last December was an advance in the Obama administration's campaign to secure all vulnerable stocks of nuclear material by 2014. While the suspension announced Friday was a sign of deepening tension between Belarus's authoritarian leader and the West, analysts said it didn't pose a serious security risk.
Belarus is the last country in the former Soviet orbit outside Russia with a large, Cold War-era stockpile of highly enriched uranium, which can be used to make nuclear bombs if enriched to a pure-enough grade.
Under the agreement, U.S. officials said, Belarus was to ship 220 kilograms (485 pounds) of uranium to Russia by 2012; Russia would change the uranium to a less-purified grade and return it. About 10% of the stockpile has been shipped to Russia, according to Viacheslav Kuvshinov, head of Belarus's state-run Joint Institute for Power and Nuclear Research.
The Belarussian Foreign Ministry said the shipments were halted because of U.S. economic sanctions that go against "the spirit of interaction and cooperation." It said they would resume "once sanctions are dropped."
Meanwhile, the uranium will remain securely stored, in line with Belarus's international commitments on nonproliferation, the foreign ministry said.
Tommy Vietor, spokesman for the U.S. National Security Council, said that the U.S. has "always viewed such nuclear-security issues as nonpolitical given their importance to international security" and that the Obama administration was "hopeful that we can find a way forward in the weeks and months ahead."
Russian officials didn't respond to requests to comment on the suspension.
The U.S. and European Union imposed travel restrictions and other sanctions against President Alexander Lukashenko and other Belarussian officials this year after Mr. Lukashenko won a new term in a disputed election and jailed many of his rivals. The new U.S. sanctions, imposed last week in response a clampdown on dissent, bar transactions with four state-controlled firms with close ties to Mr. Lukashenko.
David Kramer, director of Freedom House in Washington and a former assistant U.S. secretary of state, said Belarus was trying to use what little leverage it has with the West to roll back the sanctions.
"We shouldn't fall for it," he said. "The U.S. and Russia and EU members will have to ramp up their surveillance and monitoring of Belarus" to ensure against any proliferation of nuclear fuel, "but I don't think there's a serious threat."
Alexander Klaskovsky, an independent Belarussian political scientist in Minsk, said the country's leaders "are playing a political game," not signaling a security challenge to the West. "They understand that uranium is not a good topic for jokes." He said Belarus could face pressure from Russia, an ally and trading partner, to resume the uranium shipments.