President Joe Biden has warned Russia that the United States will not be intimidated by reckless threats after Vladimir Putin declared the annexation of four occupied regions of Ukraine.
On Friday, President Putin appeared to make a veiled threat to use nuclear weapons to defend those regions.
He said they would “forever” be Russian – but Ukraine vowed to liberate them.
Nato chief Jens Stoltenberg said the Russian move was “the most serious escalation since the start of the war”.
In a speech in Moscow, the Russian leader claimed citizens in Ukraine’s eastern Donetsk and Luhansk regions, as well as in Kherson and Zaporizhzhia in the south had voted to be “with their people, their motherland”.
He was referring to so-called referendums held in the regions in recent days, but Ukraine and Western governments have condemned the votes as a sham.
Ukraine launched a new, fast-track bid to join Nato soon after Mr Putin’s speech.
After a crisis meeting of Ukraine’s National Security and Defence Council, President Volodymyr Zelensky said Kyiv had long been a “de facto” member of the security bloc and accused Moscow of redrawing borders “using murder, blackmail, mistreatment, and lies”.
Mr Zelensky vowed to liberate all Ukrainian territories, including Crimea – Ukraine’s southern peninsula annexed by Russia in 2014. And he also ruled out any further negotiations with Mr Putin.
Meanwhile, Mr Stoltenberg of Nato was reluctant to be drawn on the bid, saying the decision rested with the bloc’s 30 members.
The alliance’s members “do not and will not” recognize any of the annexed territories as part of Russia, Mr. Stoltenberg told reporters, accusing Mr Putin of “irresponsible nuclear saber-rattling”.
He called the annexation a “pivotal moment” in the war.
EU Commission President Ursula von der Leyen said “the illegal annexation proclaimed by Putin won’t change anything”.
“All territories illegally occupied by Russian invaders are Ukrainian land and will always be part of this sovereign nation.”
Turkey described the Russian move as a “grave violation” of international law.
South Korea said it did not recognize the attempted annexations, adding that Ukraine’s sovereignty, territorial security, and independence must be protected.