Hungary will veto any European Union sanctions against Russia affecting nuclear power, Prime Minister Viktor Orban told state radio.

Ukraine has called on the EU to impose sanctions against Russia's state-owned nuclear energy company Rosatom, but Hungary, where Russia has built a nuclear power plant and which it plans to expand with Rosatom, has blocked the measure.

Orban reiterated in an interview that nuclear energy sanctions "should obviously be vetoed."

Hungary's Paks nuclear power plant has four small, Russian-made reactors with a total capacity of about 2,000 megawatts, which began operating between 1982 and 1987.

It generates about half of its capacity, and the plant gets its nuclear fuel from Russia. According to an agreement signed in 2014 with Russia, Hungary intends to expand the Paks NPP with two Russian-made reactors of 1.2 gigawatts each.