Western officials have expressed fears that Russia could unleash a terrifying new weapon which would decimate Ukraine as the conflict deepens.
Vladimir Putin could use devastating thermobaric rockets on the people of Kyiv, after they have shown fierce resistance to the Russian invasion.
Officials had already warned that Putin wanted to "decapitate" President Volodymyr Zelensky's Ukrainian government by taking over the capital.
But after thousands took to the streets armed with guns alongside Ukrainian soldiers, the Russian advance has not yet been successful in toppling the city.
Now officials are worried Putin will use thermobaric missiles, which contain a deadly concoction of highly explosive fuel and chemicals which send out supersonic blast waves that can rip buildings and bodies apart.
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At a briefing on Friday, Western officials expressed their 'serious concern' that the Russian leader would resort to such weapons, which could cause huge loss of life and turn cities to rubble.
The TOS-1 Buratino and TOS-1A Solntsepek are seen as some of the more dangerous weapons on the modern-day battlefield.
The Russian Tos-1 Buratino weapons are thought to have already crossed the border into Ukraine, and officials said their use would cause "indiscriminate violence".
Russian forces are around 19 miles from the centre of Kyiv as they face a fierce resistance.
In a televised message at 12.30am Ukrainian time, Zelensky said: "The night will be harder than the day. At night they will storm, you can not give up the capital. We must survive this night."
On Friday, Ukraine claimed it had shot down a Russian plane carrying some 100 paratroopers approximately 20km from Kyiv.
In total 2,800 Russian troops had been killed or wounded, 80 armoured vehicles destroyed and 17 jets and helicopters downed across the country by Friday afternoon, Ukrainian officials said.
But a spokesman for Mr Zelensky said on Friday night that his country is in talks with Russia to arrange a time and place for talks, adding: "Ukraine was and remains ready to talk about a ceasefire and peace."
The Russian army resumed its bombing campaign on Kyiv through the night and by Saturday morning (Feb 26), videos of missile strikes on residential buildings close to the centre had emerged.
Intelligence from the west suggested that Putin's men had hoped to take the capital within 48 hours, but the fierce contest over the city continues.
Now political tensions continue to escalate between East and West as Russian-ally and major global player, China refused to condemn the invasion of Ukraine.
Instead the country abstained on a UN Security Council resolution to condemn Russia’s “aggression” against Ukraine on Friday.
As well as having key trade partnerships, China and Russia have historically been aligned on major issues, including most recently Moscow’s military involvement in Syria.
Nato announced that it was activating its Response Force for the first time in "collective defence", meaning it is ready to fend off any incursion by Russia into Nato territory, The Telegraph said.
James Heappey, the UK Armed Forces minister, announced that the UK would send more tanks and troops to Estonia "earlier than planned" to reinforce the Nato ally in the wake of Russia's invasion of Ukraine.
As well as doubling the number of tanks there from 600 to 1,200, soldiers from the Royal Tank Regiment and Royal Welsh battle groups have been deployed to help protect the country from a Russian advance.
