Prime Minister Tony Abbott says it's not too late for a Russian change of heart when it comes to co-operating with an independent investigation into downed Malaysia Airlines flight 17.
But he fears "chaotic" interference at the crash site in eastern Ukraine will continue.
These were "wrenching times", Mr Abbott said, adding his own daughters had recently travelled on the same flight home from Europe.
"You look at the faces of the dead and they're your neighbours, they're your friends and they could even be your kids," he told ABC television.
"There are 36 people who call Australia home who have been snuffed out."
A clearly frustrated prime minister continued his tough talk over the disaster, on a day when he attended a memorial service in Sydney for the nearly 300 people killed in the disaster.
He described the crash site in rebel-controlled territory as "absolutely chaotic" and reports of pro-Russian rebels meddling with the evidence, including the removal of bodies, as "outrageous".
Sceptical about Russia's willingness to co-operate with an international investigation, Mr Abbott has dispatched Foreign Minister Julie Bishop to New York to lobby for an inquiry backed by the United Nations.
At least two attempts by international investigators to access the site had been frustrated by rebels, he said.
"My fear is that Russia will say the right thing, but that on the ground interference with the site, interference with
investigators, interference with the dignified treatment of bodies will continue," Mr Abbott said.
"It's not too late for changes of heart.
"There are excuses. There is blame-shifting. There is handwashing going on, and that's not acceptable, it's simply not acceptable."
Mr Abbott would not say if Australia would stop Russian President Vladimir Putin attending November's G20 meeting in Brisbane, amid calls that he be banned from the event.
Deputy Prime Minister Warren Truss said it would be "difficult" to welcome President Putin to Australia.
"But there'll be some time before that meeting, and we hope Russia will have taken some positive steps by then," he told Network Ten.
Greens leader Christine Milne said Australia should take a stand through the G20.
"I would certainly back a move to say no, he (Putin) shouldn't be coming to the G20," she told Sky News.
Queensland Premier Campbell Newman said Mr Putin should not be welcome in Brisbane unless he co-operated with the MH17 investigation.
Labor's Bill Shorten has also said Australia should consider barring Mr Putin from the November summit.
Mr Abbott said he had made clear his "dissatisfaction" with Russia's handling of the disaster in a meeting with its Minister for Economic Development Alexei Ulyukayev, who is in Sydney for a G20 trade ministers' gathering.
"Russian-controlled territory, Russian-backed rebels, quite likely a Russian-supplied weapon - Russia can't wash its hands of this," the prime minister said.
Mr Abbott said Ukrainian President Petro Poroshenko had invited Australia to "fully participate" in any aspect of the investigation, including body recovery.
But he warned it could be weeks before the victims' remains were returned to their families.
"The grim truth is that not all the bodies will be intact," he said.
A national day of mourning for all the Australian victims, to include a national commemorative service, will be held in the next fortnight, he said.
