Russian President Vladimir Putin has promised to cooperate with outraged world leaders seeking access to the site of downed flight MH17.
Prime Minster Tony Abbott won't say much about his 3am phone call with Putin but it's reasonable to assume it was tense.
It was their first conversation since Malaysia Airlines flight MH17 was shot down.
Russia took umbrage with Mr Abbott in the immediate aftermath of the disaster, singling him out for rebuke after he suggested Moscow had questions to answer over the attack.
Mr Abbott refused to back away when his comments made international headlines, repeating his assertion that Russian-backed rebels were most likely to blame.
The under-fire Russian leader appeared to seek to temper international fury after US Secretary of State John Kerry said the missile system used to shoot down the Malaysia Airlines jet was "transferred from Russia in the hands of separatists".
The UN Security Council is on Monday due to consider a resolution demanding that pro-Russian separatists provide "unrestricted access" to the site in rural eastern Ukraine, as concerns rise over evidence tampering, the fate of victims' remains and black boxes.
In separate phone calls, Putin promised Dutch Prime Minister Mark Rutte "full cooperation" in retrieving the bodies and black boxes, while Australia's premier Tony Abbott said the Russian leader had said "all the right things".
Both countries suffered heavy losses when Malaysia Airlines flight MH17 was blown out of the sky on Thursday by what is believed to have been a surface-to-air missile, killing 298 and dramatically raising the stakes in Ukraine's bloody three-month conflict.
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'Absolutely chaotic' at MH17 site
Pro-Russian militiamen in Ukraine loaded almost 200 bodies from downed flight MH17 into refrigerated train wagons on Sunday as an outraged United States pointed the finger of blame directly at Moscow and demanded it ensure full access to the crash site for international investigators.
In what is the most unequivocal statement incriminating Russia, US Secretary of State John Kerry said the missile system used to shoot down the Malaysia Airlines jet was "transferred from Russia in the hands of separatists".
The separatists' violent bid for independence is the latest chapter in a prolonged crisis sparked by Kiev's desire for closer ties with the EU -- a sentiment many in the Russian-speaking east do not share.
Evidence is mounting that the rebels downed the jet, pushing East-West ties already strained by the bitter tug-of-war over Ukraine's future to crisis point.
Kiev has released fresh recordings of what it says are intercepted conversations between rebels organising to hide the flight's black boxes from international monitors.
And the US embassy confirmed as authentic recordings released by Kiev of an intercepted call between an insurgent commander and a Russian intelligence officer as they realised they had shot down a passenger jet.
However, top Russian officials and state media have suggested that Kiev's new leaders staged the attack to blame the rebels.
Insurgents said they had in hand material resembling black boxes, but promised to give them to "international investigators if they arrive".
They on Sunday loaded nearly 200 bodies into refrigerated train carriages until "the experts arrive", said a rebel chief who explained that fighters had moved scores of bodies "out of respect for the families".
"We couldn't wait any longer because of the heat and also because there are many dogs and wild animals in the zone," said Alexander Borodai, prime minister of the self-proclaimed Donetsk People's Republic.
OSCE spokesman Michael Bociurkiw described the stench at Torez station, where armed separatists were guarding the grisly cargo of corpses, as "almost unbearable".
Fighting continued to rage between government forces and rebels in the east, with 13 people wounded in the last 24 hours just 100 kilometres (60 miles) from Grabove.
And Ukrainian authorities said they could not guarantee the safety of investigators on the ground.
Kerry, whose government has condemned reported evidence-tampering and lax security at the crash site, said the missile system used to down the jet was supplied by Moscow.
"We know with confidence, with confidence that the Ukrainians did not have such a system anywhere near the vicinity at that point in time. So it obviously points a very clear finger at the separatists," Kerry told CNN.
He also slammed as "grotesque" the manner in which "drunken separatist soldiers" were allegedly "unceremoniously piling bodies into trucks, removing both bodies, as well as evidence, from the site".
Australia circulated a draft UN Security Council resolution demanding the rebels give "full and unfettered access" to the crash site, and for all parties to cooperate in the probe.
The suspicion of Russian intentions was also high, with Australian Prime Minister Tony Abbott telling ABC: "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."
The leaders of France, Britain and Germany signalled they could ramp up sanctions against Russia as early as Tuesday -- barely a week after the last round of toughened embargoes.
Ukrainian Prime Minister Arseniy Yatsenyuk told a German newspaper that taking a plane down was an operation that would take professionals and not "drunken gorillas".
The Washington Post said Ukraine's counterintelligence chief had photographs and related evidence that three Buk M-1 anti-aircraft missile systems moved from rebel-held territory into Russia less than 12 hours after the crash.
The US embassy confirmed as authentic recordings released by Kiev on Thursday of an intercepted call between an insurgent commander and a Russian intelligence officer as they realised they had shot down a passenger jet.
But top Russian officials and state media have suggested that Kiev's new leaders staged the attack to blame the rebels.
Dutch Prime Minister Mark Rutte -- his shocked nation flying flags at half mast in mourning over 193 lost compatriots -- has urged Putin to "take responsibility" for a credible probe, with investigators from the Netherlands set to arrive in eastern Ukraine.
Relatives wait around world
Relatives in the dozen countries whose citizens were killed pleaded for them to be brought home.
"At this current moment I hope the world can assist the families to bring back the remains," Zulkifli Abdul Rahman, brother-in-law of one of the cabin crew, told AFP in Kuala Lumpur.
The disaster has an added poignancy for Malaysia after the March disappearance of the Kuala Lumpur to Beijing flight MH370 carrying 239 passengers and crew.
In the Netherlands, and Australia -- which lost 28 citizens on flight MH17 -- churchgoers prayed for the dead at memorial services.
Dozens of bouquets of flowers had also been laid at Schiphol airport, where the doomed flight had taken off from.
Putin has denied having any influence over the rebels, who had declared Sunday they would only accede to Western demands over the crash if Kiev agrees to a truce.
Ukrainian President Petro Poroshenko ripped up a shaky ceasefire on July 1 and has refused a new truce until the separatists who rose up against Kiev in the wake of Moscow's controversial annexation of Crimea in March give up their arms.
Poroshenko is pressing world leaders to recognise the militias as a terrorist organisation that should be put on trial at the Hague.
"We see no difference between the events in Ukraine and what happened on September 11 in the United States or the tragedy over Scotland's Lockerbie," Poroshenko said.