Russia has sent a fleet of warships towards Australia in an apparent display of muscle-flexing ahead of the G20 meeting amid tensions between the two countries over the MH17 crash.

Defence announced late on Wednesday it is "monitoring Russian naval vessels that are currently transiting through international waters to the north of Australia".

Tony Abbott speaks to Vladimir Putin in Beijing on Tuesday. Credit:Alexey Druzhinin

It stressed: "The movement of these vessels is entirely consistent with provisions under international law for military vessels to exercise freedom of navigation in international waters."

Defence Force chief Mark Binskin confirmed Defence was watching the fleet. In a reference to the fact it was a considerable distance for the Russian navy to travel, he noted one of the ships was an ocean-going tug, which tows other ships.