(London): The United Kingdom's Prime Minister Boris Johnson called Russian President Vladimir Putin a "dictator" and threatened "massive" sanctions following Russia's full-scale invasion of Ukraine.

"We cannot and will not just look away," Johnson said in an address to the United Kingdom Thursday morning.

"Diplomatically, politically, economically -- and eventually, militarily -- this hideous and barbaric venture of Vladimir Putin must end in failure," he said.

Johnson then called the attack on Ukraine "an attack on democracy and freedom in east Europe and around the world," and referred to Putin as a "dictator."

"Because for all his bombs and tanks and missiles, I don't believe that the Russian dictator will ever subdue the national feeling of the Ukrainians and their passionate belief that their country should be free."