Australia has threatened Japan with international legal action if it doesn't cease whaling.

Prime Minister Kevin Rudd said on Friday Australia was pursuing Japan through diplomatic channels, but had set a deadline for it to end whaling in the Southern Ocean.

"If that fails, then we will initiate court action before the commencement of the whaling season in November 2010," he said.

"But that's the bottom line and we're very clear to the Japanese, that's what we intend to do." Rudd said.

The Australian Greens party says in a statement on Friday Japan should be taken to the International Court of Justice during the current whaling season, not next one.

Foreign Minister Stephen Smith said in a statement on Friday he would discuss whaling and potential legal action with his Japanese counterpart Katsuya Okada when they meet in Perth on Sunday.

However, he says the meeting will focus mainly on bilateral trade.

Japan is Australia's second-largest trading partner and export market and the third-largest source of foreign investment, according to Smith.