Russian President Vladimir Putin signed a decree to recognize two breakaway regions of eastern Ukraine as independent entities in a signing ceremony shown on state television on Monday.
Putin said he was confident that Russia's citizens supported the decision, brushing off Western warnings that such a step would be illegal and would kill off peace negotiations.
"I deem it necessary to make a decision that should have been made a long time ago - to immediately recognize the independence and sovereignty of the Donetsk People's Republic and the Lugansk People's Republic", Putin said.
He added, "If Ukraine was to join NATO it would serve as a direct threat to the security of Russia."
US President Joe Biden held a secure call with Ukraine's President Volodymyr Zelenskiy on Monday in the aftermath of Russian President Vladimir Putin recognizing two breakaway regions in eastern Ukraine as independent entities.
A White House official said the call between the US and Ukrainian leaders lasted 35 minutes.
The Moscow-backed regions have been thrust to the forefront of a mounting international crisis over a Russian military buildup that has fueled fears that Moscow may be on the brink of invading Ukraine. The Kremlin denies such plans.
The rouble plumbed weeks-long lows during the meeting as Putin called on top officials including his spy chief, defense minister and two parliamentary speakers to speak from a podium about whether they supported the idea of recognition.
To kick off proceedings, Putin said he thought it was clear Ukraine would not implement the Minsk peace process aimed at ending the conflict between government forces and separatists in east Ukraine that has killed 15,000 people.
"It is clear to everyone that (Ukraine) is not going to do anything on this Minsk package of measures...," Putin said.
INTENSE PRESSURE
All 12 senior officials backed the idea of recognizing the mainly Russian-speaking regions, according to a tally by the RIA news agency, though two of them suggested briefly waiting to see if the situation might now improve with this new threat.
Recognition for the regions is likely to torpedo the Minsk peace accords, which all sides, including Russia, had previously said were the only possible route out of the crisis in eastern Ukraine.
Such a step could also pave the way for Moscow to openly send in military forces to the regions, echoing its approach to Georgia's breakaway regions of South Ossetia and Abkhazia whose independence it recognized and where it has troops garrisoned.
The televised meeting of the powerful Security Council, which usually meets strictly behind closed doors, offered an extraordinary glimpse into the intense pressure at the top of the Russian elite.
At one point, Putin told spy chief Sergei Naryshkin to be more forthright, prompting the official to blurt out that he backed the idea of Russia absorbing the regions before correcting himself to say he supported recognition.
Defense Minister Sergei Shoigu said the situation was extremely tense in the self-declared Donetsk and Luhansk people's republics that lie in Ukraine's Donetsk and Luhansk regions.
Interior Minister Vladimir Kolokoltsev said he backed the idea of recognizing the republics' dominion across the entirety of the Donetsk and Luhansk regions, much of which is under Ukrainian government control.
The head of the Federal Security Service told Putin that the security situation in Donbas was deteriorating and that 70,000 people had been evacuated from them to Russia after separatists announced a mass evacuation on Friday.
Russia's lower and upper houses of parliament are due to meet on Tuesday and would be likely involved in formalizing any move to recognize the regions.