Russia's "massive" military losses in Ukraine are unsustainable, NATO's secretary general warned with the conflict about to enter its fourth year with no clear end in sight.

Russia said on Thursday that its was unacceptable for the West to keep claiming that Russia and China threatened Greenland, and said the crisis over the territory showed the double-standards of Western powers which claimed moral superiority.

Former Putin adviser Sergey Karaganov warned that Russia would use nuclear weapons against Europe should it ever come close to defeat.

Up to 25,000 Russian soldiers are being killed every month, NATO Secretary General Mark Rutte said this week.

The United States accused Russia of "dangerous and inexplicable escalation" after new attacks on Ukraine's energy and civilian infrastructure.

Russia Foreign Ministry said in a statement the diplomat’s accreditation has been revoked and that the individual must now leave the country within two weeks. The U.K.’s charge d’affaires in Russia, Danae Dholakia, was summoned to the ministry’s Moscow headquarters to receive the notice.

Russia says it used its new Oreshnik hypersonic missile and other weapons in a massive strike on Ukraine​. Ukrainian President Zelenskyy says a drone hit the Qatar embassy.

China has stopped imports of electric power supplies from Russia, Kommersant newspaper reported on Friday, citing sources familiar with the situation and high prices, while Russia said it was ready to resume sales and talks were taking place.