MOSCOW/CHISINAU (Reuters) - Russian energy giant Gazprom said on Saturday it would suspend gas exports to Moldova from 0500 GMT on Jan. 1 due to unpaid debt by Moldova, which is bracing for severe power cuts.

It said the company reserved the right to take any action, including terminating the supply contract with Moldova.

Russia supplies Moldova with about 2 billion cubic metres of gas per year, which is piped via Ukraine to the breakaway region of Transdniestria where it is used to generate cheap power that is sold to government-controlled parts of Moldova.

Moldovan Prime Minister Dorin Recean condemned the Russian decision, which is a precursor to a total shutdown of Russian gas exports via Ukraine and to Europe, where it flows further to Slovakia, Austria, Hungary and Italy, once a current transit deal with Ukraine expires on Dec. 31.

Moldova will be hit the hardest by the shutdown.

"This decision confirms once again the intention of the Kremlin to leave the inhabitants of the Transdniestrian region without light and heat in the middle of the winter," Recean wrote on Facebook, accusing Russia of using energy as a political weapon.

Moscow has repeatedly dismissed those allegations.

DIFFERENCE OVER DEBT

Russia, which is critical of Moldova's West-leaning central government, has said Moldova should pay a debt on past supplies. According to Russian calculations, the debt stands at $709 million. Moldova has put the debt at $8.6 million.

Gazprom has said previously it wants Moldova to pay the debt before it starts to pump gas to the country via alternative routes.

Transdniestria and the government in Chisinau agreed in 2022 that all Russian gas received by Moldova would flow to the breakaway region, which traditionally does not pay for fuel.

Without gas supplies, the power-generating plant could stop working and Moldova and Transdniestria would face hours-long blackouts similar to those experienced by Ukraine due to Russia's attacks on its energy infrastructure in their war.

The government of Transdniestria told businesses that from Saturday, gas supplies would start to be switched off to commercial entities that were not considered critical.

But it said supplies of gas, heating and hot water to households would continue as usual until Jan. 1.

Recean said Moldova had diversified sources of gas supply "in order to reduce dependence on a single supplier".

"Our country is prepared to handle any situation that arises following the Kremlin's decision," he added.

Moldova's population of 2.5 million has been preparing for long power cuts since Ukraine's government said it will not extend its transit contract with Gazprom.

Moldova and Transdniestria have both declared states of emergency over the threat of disrupted gas supplies, and Moldova said on Friday it will curb power exports and introduce measures to reduce consumption by at least a third from Jan. 1.

Moldovan President Maia Sandu has accused Gazprom of provoking an energy crisis, saying it was refusing to supply gas through an alternative route.

(Reporting by Vladimir Soldatkin and Alexander Tanas; Editing by Guy Faulconbridge, Frances Kerry and Helen Popper)