UK prime minister accuses Putin's regime of using a “cynical, barbaric” playbook.
The list includes the UK and Ukraine, but Twitter users were surprised Liechtenstein, Montenegro and San Marino also made the cut.
The attack on Kharkiv took place while peace talks were going on.
The Kremlin critic was gunned down outside his home on Tuesday.
The election has once again underlined how popular the Kremlin strongman remains at home.
The diplomats are due to leave London on March 20, RIA news agency quoted Russia’s ambassador to Britain as saying.
The five things you need to know about politics today.
1. NURSING A GRIEVE-ANCE The day is finally upon us. Yes, MPs are bracing themselves for up to eight hours on the Committee
“As currently led, by fine people, I believe very much in our intelligence agencies,” said Trump.
'Be ashamed Alex, be very ashamed.'