The United Kingdom has begun supplying Ukraine light anti-tank missiles for self-defence after Russia amassed about 100,000 troops on its border.

Talking to the British parliamentarians, defence secretary Ben Wallace said that British military trainers would also be deployed in Ukraine to impart training to Ukrainian armed forces.

He said there is legitimate and real cause for concern the Russian troops could be used for an invasion.

Mr Wallace said the UK would be providing extra help with security in the light of Russia's "increasingly threatening behaviour".

Dozens of British troops have been in Ukraine since 2015 to help train their armed forces.