Several explosions have been reported across Ukraine, as Russian troops launched offensives across the region in the early hours of this morning.
More than 40 Ukranian troops are reported to have been killed so far.
The move by Russia comes following weeks of growing tensions between Moscow and Kyiv, with Western states recently imposing a range of different sanctions on Russian individuals.
Announcing the “special military operation” earlier this morning, Russian president Vladmir Putin warned that Moscow's response will be "instant" if any other nation attempted to take Russian on.
It comes days after Putin recognised the regions of Donetsk and Luhansk as independent states. Earlier in the week, the Russian president claimed that “what is happening in the Donbas today is genocide”.
The latest Russian action has been condemned by Western states.
British Prime Minister Boris Johnson said Putin "has chosen a path of bloodshed and destruction by launching this unprovoked attack".
Germany's economy minister warned Robert Habeck said Europe was awar "that we thought was only to find in history books".
And US President Joe Biden said Putin had "chosen a premeditated war that will bring a catastrophic loss of life and human suffering".