Australia will host the leaders of the Group of 20 nations at their annual meeting this weekend, with the world's major economies coming together in Brisbane for major talks. For one guest, however, there might not be a warm welcome.

Over the past few weeks, Australian Prime Minister Tony Abbott has repeatedly warned Russian President Vladimir Putin that he intended to take him to task for his government's alleged role in shooting down of Malaysia Airlines Flight 17 over Ukraine in July. Pointing to widely accepted evidence that Kremlin-backed rebels shot down the plane, Abbott has argued that Russia should not just help more with the investigation but should also pay compensation to the victims.

It's an emotional issue for many Australians -- 38 of the passengers killed on the flight were citizens of the country -- and one that the prime minister has seized on. Abbott, a conservative politician who has frequently caused controversy in Australia, went so far as to publicly threaten to "shirtfront" the Russian president -- a colloquialism from Australian rules football that means to bump someone "forcefully in the chest."

"I am going to be saying to Mr. Putin, 'Australians were murdered; they were murdered by Russian-backed rebels using Russian-supplied equipment,' " Abbott added -- though he later walked back his comments, promising only a "robust" discussion with Putin.

In the end, Abbott decided to bring forward his confrontation with Putin, challenging him for 15 minutes at the Asia-Pacific Economic Cooperation summit in Beijing on Tuesday. According to The Guardian, the Australian leader told his Russian counterpart that he had evidence that the missile launcher used to down the Malaysia Airlines plane had come from Russia and was returned to Russia afterward. Abbott pointed to the example set by the United States when it shot down Iran Air Flight 655 in 1988 and subsequently apologized and paid compensation to the victims' families.

The response may not be what Abbott was hoping for, however. Putin's spokesman, Dmitry Peskov, joked to Russian reporters that Abbott "did not even try" to "shirtfront" Putin, and on Wednesday, a representative of the Russian Embassy in Canberra flatly rejected the Australian position.

"We totally refute the allegations and we want to commit to the full and impartial international investigation," spokesman Alexander Odoevskiy told the Sydney Morning Herald. "If the prime minister has, as he declares, any clear evidence, then he should bring it to the table. We haven't seen it." Odoevskiy also told the newspaper that the situation with Malaysia Airlines Flight 17 was "incomparable" to Iran Air Flight 655 due to the lack of agreement over who was was behind the downing of the plane.

To make matters worse, Australian media are also reporting that Russia may be flexing its military muscles near Australia. 7News reported Wednesday that "four Russian warships are bearing down on Australian waters, led by the guided missile Cruiser, Varyag, the flag ship of Russia's Pacific fleet." Australia's government has downplayed this development, pointing out that the "movements of these vessels [are] entirely consistent with provisions under international law." Any direct military confrontation between the two nations certainly appears extremely unlikely, though the movement of the ships draws an interesting parallel with a number of "unusual" recent incidents involving Russian air power in Europe.

It leaves Abbott in an awkward position. For all his tough talk, an apology from Russia seems as distant as ever, and his macho "shirtfront" comment has been widely mocked; one online survey published by the conservative paper Sydney Morning Herald found that the majority of readers were unhappy with his efforts. And while Putin may receive a cold reception in Brisbane, he's probably sure he has come out on top.