Kiev's prime minister said the remains of some 250 victims of the 298 killed when the flight went down last week, apparently shot by a surface-to-air missile, had been recovered and moved to train cars, and could be transferred to the Netherlands.
But the bodies are in rebel-held territory where Kiev holds no sway, near the city of Donetsk where intense shelling broke out again on Monday.
The UN Security Council is expected today to adopt an Australia-backed resolution demanding that pro-Russian separatists grant unrestricted access to the crash site for international experts.
Patience was wearing thin over Moscow's stance, even as President Vladimir Putin pledged Russia would do "everything in its power" to resolve the Ukrainian conflict and to open access to the site.
The under-fire Russian leader appeared to seek to temper world fury after Washington said it had overwhelming evidence the missile system used to shoot down the Malaysia Airlines jet was transferred from Russia to the rebels.
After speaking with Putin, Australian Prime Minister Tony Abbott noted he had "said all the right things" but that he would "hold the president to his word".
"That is certainly my intention, and it should be the intention of the family of nations to hold the president to his word," Abbott said, as concerns rose over tampering with evidence including the victims' remains and the plane's black boxes.
Twenty-eight Australian nationals and nine residents were among the passengers from a dozen countries on the doomed flight.
At the Torez station, close to Donetsk, an AFP reporter witnessed the Dutch investigators, wearing masks and headlights, open each of the train wagons holding the remains of recovered bodies, amid an overpowering stench.