Sapporo - The Wallabies got a big boost ahead of the Rugby World Cup on Friday as rampaging wing Marika Koroibete signed a new contract with Rugby Australia, opting against joining an exodus of players overseas.

The Fijian-born star has cemented his place in the Australian team since making his debut in 2017 and will play at least another two seasons with the Melbourne Rebels.

His decision to stay in Australia comes after a host of top names, including Will Genia, David Pocock and Bernard Foley, chose to play abroad once the tournament in Japan is over.

"I am really enjoying my rugby, so it was an easy decision to stay with a club that gave me a chance to play the game," said Koroibete, who used to play rugby league for Fiji.

"My family and I are very happy in Melbourne and we have support at the Rebels that is not taken for granted."

Koroibete will come face-to-face with his home nation, Fiji, when he makes his World Cup debut on the left wing in the Wallabies' Pool D opener in Sapporo on Saturday.