Rumor has it that Obama challenged Putin to a game of golf.

CANBERRA, Australia (AP) — A Russian diplomat on Tuesday dismissed the Australian prime minister’s threat of a physical confrontation with the Russian president as immature, warning that Vladimir Putin is a judo expert.

Prime Minister Tony Abbott intends to have a one-on-one meeting with Putin on the sidelines of a summit of the world’s 20 biggest economies in Brisbane next month to demand Russian cooperation with a Dutch-led investigation into the shooting down of a Malaysia airliner in Ukraine by Russian-backed separatists with the loss of 298 lives in July.

Abbott told reporters on Monday he was “going to shirtfront Mr. Putin,” using an Australian Rules Football term for a head-on shoulder charge to an opponent’s chest aimed at knocking the opponent backward to the ground.