Ukrainian troops will beat Russia and the country will “be free” from occupation, Boris Johnson has told Ukraine’s parliament – adding that it is a fight of “good versus evil”.

The UK prime minister, who has become the first world leader to address Ukrainian MPs since Russia invaded in late February, said Ukraine had proven military experts “completely wrong”.

In a recorded address, he also told the Verkhovna Rada that the “so-called irresistible force of Putin’s war machine has broken on the immoveable object of Ukrainian patriotism”.

Mr Johnson said it was Ukraine’s “finest hour”.

“Your children and grandchildren will say that Ukrainians taught the world that the brute force of an aggressor counts for nothing against the moral force of a people determined to be free,” he said.

A further £300m of UK military aid has been announced as Ukraine continues to fight back against the Russian invasion.

It includes a counter battery radar system, heavy-lift drones, GPS jamming equipment and thousands of night vision devices.

In the coming weeks the UK will send Brimstone anti-ship missiles, Stormer anti-aircraft systems and armoured vehicles to evacuate civilians, Mr Johnson vowed.

In the bombarded city of Mariupol, it is hoped more people can be evacuated from the Azovstal steelworks on Tuesday.

More than 100, including elderly women and mothers with small children, got out of the rubble-strewn site over the weekend.

Around 200 remain inside, however. Aid workers have prepared hot food, wheelchairs and toys for those able to make their way to safety.