European Commission President Ursula von der Leyen Thursday announced 250 million euros ($249 million) in financial aid to Moldova to help it cope with the energy crisis since Russia's invasion of Ukraine.

"European solidarity with Moldova is unshakable," von der Leyen told a press conference in the capital Chisinau, announcing the "energy support package".

Under the package, Moldova is from next January to receive 100 million euros in grants and 100 million euros in loans to help it "meet its gas supply needs".

The European Union will also provide 50 million euros more for "budgetary support," von der Leyen said.

Moldova's pro-European president, Maia Sandu, has warned that her country of 2.6 million people nestled between Romania and Ukraine risks running out of gas and electricity this winter.

"This is the most serious crisis of the last three decades," Sandu said on Thursday, denouncing Russia instrumentalising its "energy resources, like weapons pointed against democracy".

Moldova is heavily dependent on Russian gas, but Gazprom is expected to reduce deliveries by half this month, according to Chisinau.

A third of its electricity came from Ukraine but Russian strikes on energy infrastructure there have led Kyiv to stop all exports to Moldova.

The impoverished nation officially applied to join the European Union just after Russia invaded Ukraine in February.

"I'm very pleased that Moldova is now a candidate country for the EU, you deserve it," von der Leyen said.

In the past year, the European Union has provided more than 840 million euros in loans and grants to Moldova, she added.

Paris will also host a donor conference on November 21 to support the impoverished country, following two similar conferences since the start of the Ukraine war.

Each of those collected about 600 million euros for Moldova.