Ukrainian President Volodymyr Zelensky on Thursday, February 24 broke off Kyiv's diplomatic relations with Moscow in response to Russia's invasion of its Western-backed neighbor, AFP reports (via NDTV).

"We broke off diplomatic relations with Russia," Zelensky said in a video message.

Analysts said Kyiv was keen to keep diplomatic channels with Moscow open because it needed to provide consular and other assistance to nearly three million Ukrainians living in Russia.

Zelensky's decision came hours after Putin launched an all-out offensive that included an air assault and ground invasions along Ukraine's northern and southern frontiers.

UK Prime Minister Boris Johnson, meanwhile, has pledged that the UK and its allies will respond “decisively” to Russia’s attack on Ukraine as he prepared to address the nation amid pressure to announce further sanctions, The Guardian reports.

The prime minister also condemned Russia’s president Vladimir Putin, saying he had “chosen a path of bloodshed and destruction” that was a “catastrophe for our continent”.

It came as Ukraine’s president declared martial law, while Russia’s military said it had targeted Ukrainian airbases and other military assets and had not targeted populated areas.