Vladimir Putin is engaging in “barbaric and indiscriminate” tactics to target civilians in the Ukraine, Prime Minister Boris Johnson has said.
He also said the Russian president had “fatally underestimated” the willingness of the Ukrainian people to fight and the resolve of the West.
The UK is considering calling for Russia to be expelled from the UN Security Council, the BBC understands.
The prime minister was speaking in Poland as he meets key European allies.
His comments came in a press conference with his Polish counterpart Mateusz Morawiecki, where he said he was “increasingly confident” Russia’s invasion would fail, adding that Mr Putin “must fail” in his aims in Ukraine.
Mr Johnson said Mr Putin was prepared to “bomb tower blocks, to send missiles into tower blocks, to kill children, as we are seeing in increasing numbers”.
Mr Johnson is set to warn in a speech that Ukraine’s occupation would have “grave” consequences for the global order.
The Russian army continues its advance on Kyiv, with satellite images spotting an armoured convoy about 40 miles long.
Air-raid sirens were sounded again in the capital overnight, and there were also reports of fierce shelling in other cities including Chernihiv in the north.
The fighting escalated on Monday, with missiles killing dozens of civilians in Kharkiv, Ukraine’s second city. President Volodymyr Zelensky described the bombardment as a war crime.
In other developments:
- International Criminal Court (ICC) prosecutor Karim Khan has said he plans to open an investigation into alleged war crimes in Ukraine
- Foreign Secretary Liz Truss is expected to tell the UN Human Rights Council later that the Kremlin is breaching human rights on an industrial scale, paving the way for a UN resolution that could go as far as expelling Russia from the Security Council
- On Monday, she set out further sanctions, including powers to prevent Russian banks from clearing payments in sterling
- Defence Secretary Ben Wallace described President Putin’s order to put its nuclear forces on from what was going wrong with the invasion
- Oil giant Shell said it would end all of its joint ventures with Russian energy company Gazprom
Mr Johnson will later meet Estonian leaders and Nato secretary-general Jens Stoltenberg and is due to discuss the response to the unfolding humanitarian crisis on Ukraine’s border, as well as European security.
He will also speak to British troops serving in Estonia – which shares a border with Russia.
The prime minister is set to promise further sanctions on Mr Putin’s allies and tell the British people that there will be a cost to the economy, for example in higher energy bills, the BBC understands.
He will also say there are 1,000 British troops on standby to help with the humanitarian response in Europe.
Meanwhile, Deputy Prime Minister Dominic Raab has warned that Russian President Vladimir Putin could retaliate with increasingly “heavy-handed tactics” if his invasion of Ukraine faces further hitches.
He told BBC Radio 4’s Today programme: “We can expect, for every stutter and stumble, him to try and come back for even more heavy-handed tactics, but that is a sign that the initial phase at least – and this is going to be a long haul – has not lived up to his expectations.”
Shadow defence secretary John Healey said the Labour party would support the UK government in responding to the invasion, adding: “The most important thing is there is a united UK voice, standing with the Ukrainians.”
Military tactics researcher Dr Jack Watling said the West was trying to provide aide far too late and as a result that aide, including arms shipments announced over the last few days, was “essentially building up in Poland”.
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How best to help Ukrainian refugees may be one subject Mr Johnson will discuss with his Polish counterpart. Poland says it has been trying to process more than 300,000 people who have fled from Ukraine.
The UK government is facing calls to make its visa rules clearer and to match the European Union’s offer to accept Ukrainian refugees for up to three years, without asking them to apply for asylum.
On Monday evening, Home Secretary Priti Patel said the government was working on the possibility of helping Ukrainian refugees come to the UK.
She told ITV’s Peston programme further changes to the UK’s policy would be announced in the next few days.
Hours earlier Ms Patel had told MPs she would not waive the visa requirement for Ukrainians fleeing the conflict, saying security checks were a “fundamental” part of the approval process.
The government has already made changes to visa rules allowing anyone settled in the UK to bring some close Ukrainian family members to join them.
On Tuesday, the Archbishop of York said the government was “lagging behind” in providing safe and easy routes for refugees, as they must acquire a visa before being able to come to the UK.
Stephen Cottrell told BBC Radio 4’s Today programme there was an urgent need to help the thousands of people “in the most desperate situation” who have fled to neighbouring countries like Poland.
“There are many flights from Poland every day and people can’t get on them because they don’t have a visa. We need to change this urgently,” he added.
