NATO foreign ministers will on Wednesday seek to reassure fragile countries in Russia's neighbourhood that they fear could be destabilised by Russia as the conflict in Ukraine drags on, squeezing energy supplies and pushing up prices.

NATO allies on Tuesday pledged more help to Ukraine to repair energy infrastructure heavily damaged by Russian bombardments in what the defence alliance's chief said was Moscow using the cold winter weather as "a weapon of war".

Speaking on Tuesday Secretary-General Jens Stoltenberg said the 30-member alliance would hold talks with Moldova, Georgia and Bosnia-Herzegovina, countries "facing pressure from Russia."

"We will take further steps to help them protect their independence, and strengthen their ability to defend themselves," he said, adding it was in NATO's interest to ensure their safety.

Moldova, wedged between Ukraine and Romania, last week warned its people to brace for a harsh winter as it was facing an "acute" energy crisis that risked stoking popular discontent.

It has also faced an unresolved separatist conflict for 30 years. A contingent of Russian peacekeepers is based in mainly Russian-speaking Transdniestria that borders southwestern Ukraine.

Russian-backed separatists control two breakaway regions of Georgia - Abkhazia and South Ossetia. In 2008, Moscow said they were under threat from the Georgian government and briefly invaded other parts of Georgia.

Bosnia has been going through its worst political crisis since the end of the Balkan wars of the 1990s, with Bosnian Serbs challenging state institutions as part of their longtime bid to secede, emboldened by at least tacit support from Russia.

NATO ministers will also talk about how to strengthen the resilience of society, days after Stoltenberg warned Western nations must be careful not to create new dependence on China as they wean themselves off Russian energy supplies. (Reporting by John Irish, Sabine Siebold, Luiza Ilie; Editing by John Chalmers)