Kevin Rudd, Australia's prime minister, gave Japan an ultimatum yesterday to end its annual whale hunt in Antarctic waters.

The warning to Japan, an important trade and security partner, was delivered on the eve of a visit by Katsuya Okada, the foreign minister.

Mr Rudd has threatened since 2007 to take Japan to the International Court of Justice over the hunt, which is conducted under an exception for scientific research within the international moratorium on commercial whaling, but has not set a deadline.

“If we don't reach a landing point with the Japanese diplomatically, that action will occur well before the commencement of the next whaling season, which is this November,” Mr Rudd told Australian television.

Mr Okada, who is due to meet Mr Rudd today, played down the potential showdown as he left Japan, telling reporters: “I do not think we have major differences” since both countries were still seeking dialogue on the issue.

“Japan and Australia have very important friendly ties and I would like to discuss this calmly through those ties,” he said.

Japan's fleet kills hundreds of whales each year under the research programme, which channels the animals' meat to schools and supermarkets in Japan. Japan's Institute of Cetacean Research defends this practice under a treaty requirement that resources are not wasted and says income from meat sales goes to research.

Consumption of whale meat in Japan increased significantly after the second world war. However, the tradition of eating the meat has waned over the years with many younger Japanese having never tried it, while restaurants serving whale meat are rare.

Japan's position on hunting large sea mammals has been put further into the spotlight this year following the success of The Cove, the Oscar-nominated film that explores the country's dolphin-hunting practices.

Mr Rudd has faced a sharp drop in opinion polls since Tony Abbott took over as the opposition leader late last year.

The government has been taunted repeatedly over a spate of broken election promises on healthcare, education and housing.

An election is due later this year, galvanising Mr Rudd's efforts to make good some of those promises, such as ending whaling.