MOSCOW (AFP) - Moscow has thrown down the gauntlet to Australian Prime Minister Tony Abbott after he threatened to "shirtfront" Russian President Vladimir Putin at the Group of 20 summit next month over the loss of Australian lives in the MH17 plane crash.

Mr Abbott ramped up the rhetoric against Moscow this week by warning he would tackle Mr Putin on the issue at the meeting in Brisbane, using the Australian Rules Football sporting term in which a player charges an opponent.

But Russian Prime Minister Dmitry Medvedev laughed off the threat, saying that judo black-belt Mr Putin was unlikely to be scared of encountering the Australian leader. "If he likes to use sport terms, let him go ahead. Mr Putin is quite adept at sports and they could have a forceful debate," Mr Medvedev joked in an interview with American channel CNBC aired on Wednesday. "That said, serious politicians should chose their words carefully."

Relations between Moscow and Canberra have hit rock bottom since a Malaysia Airlines passenger was shot down over eastern Ukraine in July, killing all 298 people on board - including 38 Australian citizens or residents. Australia - along with the United States - accuses Russian-backed rebels of shooting down flight MH17 using a missile supplied by Moscow. Russia has repeatedly denied the claim and pointed the finger at Kiev.

An initial report by Dutch investigators issued last month found that the jet was hit by multiple "high-energy" objects but did not apportion blame.

Any confrontation between the two alpha-male leaders could be a feisty affair as both are famed for their macho public displays of sporting prowess.

Former KGB officer Putin has been pictured riding horses bareback across Siberia, tagged an endangered tiger and hugged a polar bear in the Arctic.

Meanwhile, fitness fanatic Abbott - who boxed for Oxford University as a student - completed a gruelling triathlon as opposition leader and regularly goes on lycra-clad cycle rides.

There had been question marks over whether Mr Putin - who faces growing isolation over his stance on Ukraine - would attend the G-20 summit in Brisbane but Australian officials confirmed this week that he is due to show up.