Prime Minister Tony Abbott’s pledge to “shirtfront” Vladimir Putin at next month’s Group of 20 summit is unlikely to cow the Russian president, a black-belt in judo celebrated at home for his physical prowess.

“I’m going to shirtfront Mr. Putin -- you bet I am,” Abbott, a former student boxer, told reporters yesterday. “I’m going to be saying to Mr. Putin, Australians were murdered and they were murdered by Russian-backed rebels using Russian supplied equipment. We are very unhappy about this.”

A Russian diplomat in Australia called the remark of Australian PM Tony Abbott about his intention to “shirtfront” Vladimir Putin “immature.” He reminded the Aussie politician that he might be “very fit” but Putin is “a professional judo wrestler.”

Vladimir Putin's official spokesman has described Prime Minister Tony Abbott's comments about "shirtfronting" the Russian leader as "very unfortunate".

Russian prime minister Dmitry Medvedev has responded to Mr Abbott's comments, and is warning Australia's PM to "choose his words carefully".

"If he likes to use sports terms, let him go ahead," he told CNBC through a translator.