Prime Minister Tony Abbott has warned Russian President Vladimir Putin to "back off" from invading neighbouring Ukraine.

On Saturday Putin won parliamentary approval to send troops into the Ukraine - a direct rebuff to Western leaders, including US President Barack Obama, who repeatedly urged Russia not to intervene. Unmarked troops – some in vehicles with Russian number plates - have already seized Crimea, an isolated peninsula on the Black Sea.

"This is very, very concerning and I think that every Australian, and people right around the world, will be thinking: hands off the Ukraine," Mr Abbott told Channel Ten's Bolt Report on Sunday morning. "This is not the kind of action of a friend and neighbour and I think Russia should back off."

Mr Abbott said he understands the issue will be discussed "urgently" by the members of the United Nations Security Council, including Australia.