Claims Japan could re-work whaling program

Prime Minister Tony Abbott says Japan should "appropriately reflect" on the international court's ruling about its whaling program, but insists trade remains the top priority for his trip to Tokyo.

The International Court of Justice has declared Japan's whale hunt in the Southern Ocean illegal, and Mr Abbott is facing pressure to raise the issue with his counterpart, Shinzo Abe, next week.

The court backed Australia's case that Japan's whaling program wasn't for science, and demanded it cease it with immediate effect.

The decision was celebrated in Australia and New Zealand, and while Japan expressed disappointment it insists it will abide by the ICJ ruling.

Mr Abbott, who will travel to Tokyo next week in a bid to finalise a free trade agreement with Japan, said the bilateral relationship was much bigger than any disagreement over whaling.

"It's now up to Japan to appropriately reflect on the judgement, and I'm sure that's exactly what will happen," he told reporters in Perth on Tuesday.

"Japan is an exemplary international citizen."

Greens Senator Peter Whish-Wilson said Japan could find a way around the ruling, and Mr Abbott should seek a guarantee from Prime Minister Abe himself that the hunt was over.

"I expect whales to be on the agenda next week, not just wheat and wagyu beef," Senator Whish-Wilson told reporters in Hobart.

But Mr Abbott said finalising the FTA remained the "absolute priority" at the moment.

Former attorney-general Mark Dreyfus, who helped bring Australia's case to The Hague, said "on paper" the judgement could leave the door open for future hunts but he believed Japan would abide the ruling.

He called on the federal government to work with Japan on non-lethal whaling research, such as using satellite trackers to monitor movements and diet.

Some international law experts have pointed out that Japan could redesign their whaling program to get around the problems identified in the ICJ judgement.