A fleet of Russian warships is steaming towards Australia - a defiant show of force from the super power ahead of this weekend's G20 meeting of world leaders.
In diplomatic terms it's a worrying development for the Abbott Government after its attack on Russia's role in the downing of flight MH17.
Leaving China on Wednesday morning, Tony Abbott had precious little to say about his exchanges with Vladimir Putin at APEC.
However, the Prime Minister likely already knew of a developing security issue that could take his problems with President Putin to a whole new level.
7News has been told four Russian warships are bearing down on Australian waters, led by the guided missile Cruiser, Varyag, the flag ship of Russia's Pacific fleet.
Also heading south is the destroyer, Marshal Shaposhnikov - it's not short of firepower either.
They are being supported by the salvage tug Fotiy Krylov and supply tanker Boris Butoma.
The task group is in the Coral Sea South of Bougainville and appear on course for waters off Australia's east coast.
All four could be sitting off Brisbane by Saturday.
Defence has sent a P3 Orion Surveillance Aircraft to shadow the ships and an Anzac class frigate, HMAS Stuart, to the Coral Sea.
"Defence is monitoring Russian naval vessels that are currently transiting through international waters to the north of Australia," Australia's Defence Force said in a statement.
"The movements of these vessels in entirely consistent with provisions under international law for military vessels to exercise freedom of navigation in international waters.
"Questions regarding the vessels should be directed to Russian authorities."
The ships arrived with no official notice from Moscow but that Australian intelligence services picked them up some days ago, 7News political editor Mark Riley reported.
Russian presidents have had naval vessels sitting offshore of international meetings a couple of times in the past but certainly not four - and not without official notice to the host country.
The timing is unmistakable; Brisbane's G20 this weekend. President Putin is a guest, though Australia has made few if any foreign leaders less welcome in the lead up to their visit.
A question now for the Abbott Government: might the Russian vessels seek a port visit? How would Australia respond?
Even in international waters off the Australian Coast, the ships are a headache for Prime Minister Abbott and right or wrong, will be read as a pointed comeback to the PM leading the charge in the MH17 case.
Prime Minister Abbott's office says his fifteen minute one-on-one with the Russian President yesterday directly tackled Russia's apparent links to the July MH17 atrocity - Abbott laying out intelligence that shows the missile launcher used to fire on the Malaysian passenger jet had been moved from Russian territory to Ukraine before the deadly strike.
But that got a swift response from the Russian embassy, its spokesman telling 7News the Kremlin "unconditionally refutes the accusation."
Suddenly the diplomatic temperature is rising ahead of Brisbane's G-20.