Prime minister Boris Johnson said Vladimir Putin's "barbaric actions" on Ukraine are testing "all of humanity". He made the remarks after his latest telephonic conversation with Ukrainian president Volodymyr Zelensky on Sunday.
Mr Johnson pledged that the UK would continue to do "all that we can" to end "this disastrous conflict".
Meanwhile, Liberal Democrat leader Sir Ed Davey has urged the prime minister to fire home secretary Priti Patel over her "utterly shameful" response towards the Ukrainian refugees.
In a speech at the party’s spring conference on Sunday, the Lib Dem leader said: “She has answered desperation with delays; crisis with confusion; pain with paperwork".
“It couldn’t be clearer that Priti Patel is not up to the job. The buck stops with the prime minister. So Boris Johnson must sack her now,” he added.
The UK government last week sanctioned 386 members of the Duma - the lower house of the Russian parliament- for their support to recognise the Ukrainian breakaway regions of Luhansk and Donetsk as independent entities.
