Russia says Ukraine's deal to buy U.S.-made nuclear fuel for its Soviet-built reactors could trigger a nuclear accident.

Prime Minister Arseniy Yatsenyuk of Ukraine announced Tuesday that his nation has reached a deal on nuclear fuel deliveries with Westinghouse to reduce dependence on Russian supplies.

Russia's Foreign Ministry deplored the move as a "dangerous experiment that threatens safety and health of the Ukrainian citizens and peoples of Europe." It said nuclear fuel produced by the U.S. company doesn't quite fit Soviet-built nuclear reactors that Ukraine has.

The ministry said Ukrainian authorities must take a responsible approach to nuclear safety, or risk disasters such as the 1986 Chernobyl one, which was a result of a flawed Soviet reactor design coupled with serious mistakes made by the plant operators.