The UK is doing “everything possible” to support the people of Ukraine in the face of a Russian “disinformation campaign,” Prime Minister Boris Johnson has said.

He told the Cabinet on Tuesday that Russian President Vladimir Putin “must not be allowed to rewrite the rules” of international relations as tensions mount along the Ukraine-Russia border, according to Johnson’s spokesman.

The UK has promised anti-tank weapons to Ukraine in response to a Russian military build-up on the border, with around 100 British troops involved in a training operation.

Defence Secretary Ben Wallace lawmakers on Monday that Britain was supplying light anti-armour defensive weapons, with a “small number” of UK personnel travelling to the country to provide training.

The prime minister’s official spokesman said: “There is a small infantry training team deploying to assist the Ukrainian armed forces to become familiar with the defensive systems we are providing and ensure they are able to use them as soon as possible.

Operation Orbital, our training deployment in Ukraine, has a routine commitment of around 100 personnel – that will fluctuate depending on the type of training taking place.”