VLADIMIR Putin has warned "unparalleled" hypersonic missiles are ready for action and has been stockpiling blood, fuelling war fears.
Troops have also been on the move amid concern Ukraine's second largest city, Kharkiv, could be next in his sights, as the country declares a state of emergency.
With a huge 200,000 strong force encircling Ukraine, the world is on a knife edge waiting for Putin's next move - which could see the bloodiest conflict in Europe since WW2.
Ukraine has now declared a state of emergency, allowing police to carry out random checks, and also announced all citizens will now be allowed to carry guns.
Putin has given a chilling warning that “weapons without parallel in the world have been put on combat duty”.
His threat was delivered on Defender of the Fatherland Day - three days after he watched two of the new missiles tested from a Bond villain style “situation room”.
The latest on the crisis in Ukraine...
- Britain will 'inflict pain' on Putin, Foreign Secretary Liz Truss has said.
- A trapped family family spoke of their hell living in the blitzed corner of Ukraine
- Russia has warned it won't stop at rebel enclaves, fuelling fears it will advance into territory held by Ukrainian forces
- Britain is to send more weapons to Ukraine as Boris Johnson said Putin was behaving in “an illogical and irrational frame of mind”.
- Lord West, former chief of the Royal Navy, warned one wrong move could spark a nuclear war.
- Donald Trump has praised Putin's "genius" plan to invade Ukraine.
“We will continue to develop advanced weapons systems - including hypersonic," he said.
Moscow is urgently seeking medics to work in makeshift hospitals and has also been stockpiling blood supplies.
US President Joe Biden said intelligence suggested Russian forces were moving "supplies of blood and medical equipment" to the Ukrainian border as they prepared for an invasion.
"Russia has moved supplies of blood and medical equipment into position on their border," Biden said.
"You don’t need blood unless you plan on starting a war."
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Shelling has been continuing along the 250-mile front between Ukraine and the rebel areas.
One Ukrainian soldier was killed and six more sustained injuries after shelling by the rebels, the country's military said.
Separatist officials reported several explosions on their territory overnight and three civilian deaths.
Meanwhile, a huge column of around 100 military vehicles was seen in the Belgorod area, over the border from Krarkiv, raising fears Russia won't stop at in the rebel areas.
Tanks were also seen reinforcing the two rebel held areas, while massed Russian attack helicopters were seen in Belarus, near the border with Ukraine.
Kharkiv was earmarked by the Kremlin as the capital of a Russian-speaking, pro-Moscow state in eastern Ukraine.
Russia said it was assisting "peacekeeping" in the Donetsk People’s Republic and the neighbouring Luhansk People’s Republic, as the rebel areas are officially known, following the shelling.
🔵 Read our Russia - Ukraine live blog for the very latest updates
But fears the tank movements were only the start of a wider Russian offensive were soon fuelled by announcements from Moscow.
Hours after tanks and 10,000 troops moved into pro-Russia breakaway enclaves, the Kremlin said further territory held by Ukrainian forces should belong to the two self-declared republics.
Kremlin spokesman Dmitry Peskov said Russia has recognised the rebel regions in borders that existed when they proclaimed their independence in 2014.
This includes areas in eastern Ukraine which are currently held by Ukrainian forces on the other side of the 250-mile entrenched "contact line".
Russian MP Leonid Kalashnikov, a Putin loyalist, said his country would recognise the whole of Donetsk and Luhansk regions - rather than just the areas currently under rebel control.
And in a blatant threat to Ukraine’s existence, Foreign Minister Sergei Lavrov said Russia did not recognise its democratic neighbour's right to sovereignty.
Mr Putin himself has said Russia recognizes Donetsk and Luhansk "within borders outlined in their constitutions".
Governor of the Kharkiv region Oleh Synehubov said he is preparing for a Russian attack and says there is a "clear plan of action" to evacuate the city of 1.5 million.
In response to Russian action, President Joe Biden has ordered US troops, jets and helicopters to Eastern Europe in response to Vladimir Putin's invasion of rebel-held Ukraine.
The US president said he would continue to provide "defensive assistance" to Ukraine as he announced the authorisation of additional forces in Estonia, Latvia and Lithuania.
And he announced the US would immediately block the Russian government from using Western financial markets to raise money.
"We still believe that Russia is poised to go much further in launching a massive military attack against Ukraine," he said.
"There are still well over 150,000 Russian troops surrounding Ukraine, and as I said, Russian forces remain positioned to Belarus to attack Ukraine from the north, including warplanes and offensive missile systems."
Slapping down Putin's peacekeeping claims, Mr Biden said "none of us should be fooled" - adding he expects the Kremlin to start a war.
The move came as the European Union agreed a package of sanctions against the country, with EU foreign affairs policy chief, Josep Borrell, warning of a "particularly dangerous moment for Europe".
The staunch Putin loyalist said sovereignty was only for countries that represent all of their people – and he repeated Russian claims that Kyiv had failed to represent its ethnic Russians.
“Nobody can assert that the Ukrainian regime, starting with the state coup of 2014, represents all the people who live on the territory of the Ukrainian state,” he said.
The word "coup" was a reference to the toppling of pro-Kremlin Ukrainian president Viktor Yanukovych, who quit after protests exactly eight years ago to the day.
Putin himself then added to the tension when he asked the Russian parliament for the use of the country's military abroad.
Putin ordered the troops into the rebel areas under the guise of "peacekeepers" - a claim quickly dismissed as "nonsense" by the United States.
Already the situation is being compared to the 1962 Cuban Missile Crisis, when America and Russia were locked in a 13-day standoff that brought the world to the brink of nuclear war.
Health Secretary Sajid Javid was asked by the BBC if the situations were comparable, and replied: "I would agree with that analysis. I do think it's as serious a situation as that."
And General Sir Richard Sherriff, Britain's former top Nato commander, said: "This is the most dangerous moment in Europe probably at least since 1962 and the Cuban missile crisis."
He added Putin's "invasion of a sovereign country could turn into a catastrophic war on a scale not seen in Europe since 1945".
The much feared Russian advance began in the early hours, soon after Putin announced he recognised Luhansk and Donetsk as independent states in a bombastic TV address.
The first indication Russian forces were moving cam in footage of Terminator-style Russian forces filmed in arriving in the breakaway areas.
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Their arrival was greeted with celebratory fireworks and Russian flags were waved.