The video appearance by Ukraine’s president in a packed Commons earned an unprecedented two standing ovations. He urged MPs to provide more help to ensure “Ukrainian skies are safe”. Hours later, Poland announced all 27 of its Soviet-built MiG-29 fighter jets, which Ukrainian pilots are trained to fly, will be sent to a US airbase in Germany to bolster Kyiv’s brave military effort.

Meanwhile, Boris Johnson declared a UK ban on importing Russian oil “will punish the regime of Vladimir Putin for invading Ukraine”. The boycott will include Russian gas later.

The charismatic president delivered his resilient live address from a secret location in his war-torn country where he has evaded hit squads sent by Kremlin chiefs.

Channeling an iconic speech by Britain’s Second World War prime minister Sir Winston, he pledged that outnumbered Ukrainians will face down Putin’s invaders.

He said: “We will not give up and we will not lose. We will fight until the end, at sea, in the air. We will continue fighting for our land, whatever the cost.

Russia 'has gone all in': Does Putin have a way out of his war in Ukraine?

“The challenge is this: Putin continues to press this aggression, and that is why we are concerned this could go on for some time,” a State Department spokesperson said.

Tensions are rising in Europe’s ex-Soviet Baltic nations that President Vladimir Putin might not stop at invading Ukraine and could have his sights set on them.

Baltic states in north-eastern Europe, which are now members of the EU and NATO, were invaded and occupied in June 1940 by the Soviet Union. They remained within the USSR until its collapse in 1991.

“Clearly Putin is now in some kind of aggressive war mood,” European Commission Vice President Valdis Dombrovskis said.