Ukraine's President Volodymyr Zelenskyy has vowed that the Ukrainian people will 'fight back'

Ukraine's President Volodymyr Zelenskyy earlier tonight vowed that the Ukrainian people will 'fight back' if Putin threatens their freedom and lives by launching a full-scale invasion.

President Zelenskyy made an emotional address to his nation after Moscow-backed rebel leaders in eastern Ukraine asked Putin for military assistance in fending off Ukrainian 'aggression' - a move which has fuelled fears the Russian strongman will use it as an excuse to invade Ukraine.

In an emotional televised address tonight, President Zelenskyy said: 'The people of Ukraine and the government of Ukraine want peace.

'But if we come under attack, if we face an attempt to take away our country, our freedom, our lives and lives of our children, we will defend ourselves. When you attack us, you will see our faces, not our backs.'

The Ukrainian President said he had tried to call Putin this evening, but there was 'no answer, only silence', adding that Moscow now has around 200,000 soldiers by Ukraine's borders.

The United Nations Security Council quickly scheduled an emergency meeting Wednesday night - the second in three days - at Ukraine's request. Ukrainian Foreign Minister Dmytro Kuleba called the separatists' request 'a further escalation of the security situation.'