Russia on Wednesday declared 85 diplomats from France, Spain, and Italy "persona non grata" in a retaliatory move, effectively ordering their expulsion, as the war in Ukraine rages on.

European Union foreign policy chief Josep Borrell has voiced the bloc's readiness to defend Finland and Sweden in the event of a Russian attack even before the two countries become NATO members.

Russia says the latest push by Sweden and Finland to join NATO will only make the matters worse.

NATO has pledged open-ended military support for Ukraine, as Finland and Sweden formally announced their bid to join the military alliance.

US Secretary of State Antony Blinken says he is confident that Sweden and Finland will join NATO.

Ukrainian Foreign Minister Dmytro Kuleba said on Sunday "more weapons and other aid is on the way to Ukraine".

Russia says it would take precautionary measures if NATO deployed nuclear forces and infrastructure closer to the country's border. 

Russia is likely to suspend electricity supplies to Finland this weekend as Helsinki seems adamant about pursuing its ambitious bid of joining the US-led NATO military alliance amid the raging war in Ukraine.

Security experts warn that further confrontation between the West and Russia seems inevitable as Finland looks set to become the 31st member of the NATO military alliance.

The US and some European governments say they will support Finland and Sweden in their bid to join the NATO military alliance amid the raging war in Ukraine.