Malaysia's deal with pro-Russian rebels on MH17 caps an official response to the disaster that is being hailed at home as a swift and clear counterpoint to the government's widely mocked reaction to the disappearance of MH370.

The leadership of Prime Minister Najib Razak has been put to the test again by yet another tragic and complex air disaster just four months after the still-unexplained disappearance of Malaysia Airlines flight 370 rocked his country.

Evidence has been tampered with on an "industrial scale" at the crash site of Malaysia Airlines Flight MH17, Australian Prime Minister Tony Abbott said Tuesday, calling it "a cover-up".

Abbott, whose government was behind a U.N. Security Council resolution that Monday unanimously demanded full access to the site in rebel-held east Ukraine, admitted progress had been made but said more needed to be done.

Pro-Russian separatists in eastern Ukraine on Tuesday handed over two black boxes recovered from the crash site of the MH17 jet to Malaysian officials at a press conference.

With the backing of Russia, the U.N. Security Council on Monday unanimously adopted a resolution condemning the downing of a Malaysian passenger jet and demanding crash site access in rebel-held east Ukraine.

Australia took the lead in drafting the resolution that was adopted after some changes were made to satisfy Moscow.

Malaysian Prime Minister Najib Razak said early Tuesday that the remains of those onboard crashed Flight MH17 will be handed over to the Netherlands after striking a breakthrough deal with Ukrainian separatists.

The Malaysian premier said he had received assurances from the prime minister of the self-proclaimed Donetsk People's Republic, Alexander Borodai, that the remains of 282 people will be moved by train to the Ukrainian city of Kharkiv and handed over.

Canada's prime minister announced Monday further economic sanctions against Russian entities and individuals, saying the downing of flight MH17 was a "direct product of Russia's military aggression and illegal occupation" of Ukraine.

"The outrageous and criminal act of shooting down a civilian airliner last week is a direct product of Russia's military aggression and illegal occupation of Ukraine, and demonstrates the need for the international community to continue applying pressure on the Putin regime," Prime Minister Stephen Harper said in a statement.

A bereaved Dutch father has written a savagely ironic open letter to whoever shot down flight MH17, "thanking" them for killing his 17-year-old daughter Elsemiek, "my dear and only child".

"Thank you very much Mr (Russian President Vladimir) Putin, separatist leaders or the Ukrainian government, for murdering my dear and only child," Hans de Borst said in the letter published by Dutch media on Monday.

Britain will push for EU sanctions targeting whole sectors of the Russian economy in the wake of the Ukraine plane disaster even if it means taking a short-term "hit" to the economy, its ministers said on Monday.

Deputy Prime Minister Nick Clegg said "the time has now come for sanctions to be tightened further", and stressed that inaction so far over the Ukraine crisis had "not served us well".

Russia on Monday said its flight records show a Ukrainian fighter jet was flying close to the Malaysian passenger airliner just before it crashed and that Kiev was operating radar stations used for missile systems.

Moscow also denied supplying Ukrainian separatists with Buk missile systems or any other weapons, as it sought to head off international accusations it was responsible for the downing of the Malaysian plane with 298 people on board.

Russian President Vladimir Putin said on Monday it was essential for international investigators to be granted safe access to the crash site of flight MH17 in Ukraine.

In a video address released by the Kremlin in the early hours of Monday, Putin vowed that Russia will do all it can to bring about a settlement of the Ukraine conflict following the downing of the Malaysian passenger plane last week.