The head of Moldova’s breakaway region Transnistria has urged residents to burn firewood for heating and warned that blackouts cannot be avoided, after Moscow stopped supplying gas via Ukraine.

Russia’s state-owned energy giant Gazprom says it will halt gas supplies to Moldova starting on Jan. 1, citing alleged unpaid debt by the east European country.

"Russia is revealing the inevitable outcome for all its allies — betrayal and isolation," Moldovan Prime Minister Dorin Recean said on Jan. 3.

Gazprom has ceased gas exports to Europe via Ukraine after its transit deal expired. This marks the end of a historically contentious relationship since Crimea's annexation in 2014. The EU has been seeking energy alternatives amid the ongoing Ukraine conflict.

The severing of one of Russia's last gas export routes to Europe is being felt most painfully in a small, mainly Russian-speaking breakaway region of Moldova that has for decades looked to Moscow for protection.

Moscow breakaway region of Transnistria halted almost all industrial activity except for food production, following the end of Russian gas flows through Ukraine, Interfax reported.

Russian-owned gas giant Gazprom announced in December it would halt gas supplies to Moldova over a dispute over an alleged $709 million debt for past supplies.

The cut-off of Russian gas supplies to Moldova's breakaway Transdniestria region has forced the closure of all industrial companies except food producers, an official said on Thursday.

Russian gas has stopped passing through Ukraine after a five-year deal expired, leaving Moldova at risk of a crisis.

Moldova's Transnistria region has been thrust into an energy crisis following the termination of a gas transit agreement between Russia and Ukraine.