The US President says Russian troop deployments in eastern Ukraine are the "beginning of an invasion".
Joe Biden's comments follow the Kremlin's decision to recognise the independence of two regions.
Russia's President insists they'll be peacekeepers - but his upper house of Parliament’s backed his request allowing personnel to use force.
In response America, Canada, the UK and EU have all announced sanctions on financial institutions and people close to Vladimir Putin.
European Commission President, Ursula von der Leyen, says Russia's actions are unacceptable.
"This decision violates the territorial integrity and the sovereignty of Ukraine.
"Russia is not respecting its international obligations and it is violating core principle of international law."
