Japan proposed an end to a decades-old ban on commercial whaling at an international conference Monday, arguing there is no longer a scientific reason for what was supposed to be a temporary measure.

But the proposal faces stiff opposition from countries that argue that many whale populations are still vulnerable or, even more broadly, that the killing of whales is increasingly seen as unacceptable. Japan currently kills whales under a provision that allows hunting for research purposes.

"Science is clear: there are certain species of whales whose population is healthy enough to be harvested sustainably," reads the Japanese proposal, presented Monday at the biannual International Whaling Commission meetings taking place this week in Florianopolis, Brazil. "Japan proposes to establish a Committee dedicated to sustainable whaling (including commercial whaling and aboriginal subsistence whaling)."

Japan's proposal would also change how the international body operates, reflecting its frustration with an organization that it says has become "intolerant" and a "mere forum for confrontation."

While Japan argues that whale stocks have recovered sufficiently to allow for commercial hunting, conservationists contend whaling on the high seas has proven difficult to manage.

"Time and again, species after species has been driven to near extinction," said Patrick Ramage, director of marine conservation at the International Fund for Animal Welfare.

It's not clear when the vote will happen; the meeting lasts until Friday. It's also possible that the Japanese could pull back the proposal — or attempt to negotiate the inclusion of parts of it in other proposals.

Japan has hunted whales for centuries as a cheaper alternative source of protein to meat. Its catch has fallen in recent years in part due to declining domestic demand for whale meat and challenges to its hunt.

Its quota is now 333, about a third the number it used to kill before the International Court of Justice ruled in 2014 that its programme wasn't scientific in nature. It revised the program and resumed the hunt in 2016.

The research program remains controversial, however, and some contend it is a cover for commercial whaling because the whale meat is sold for food.

The attempt to reintroduce commercial whaling could draw even more opponents. Brazil has submitted a proposal that says such whaling "is no longer a necessary economic activity, has systematically reduced whale populations to dangerously low levels." The United States agrees that the ban is necessary for conservation.

"The Australian people have clearly made a decision that they don't believe that whaling is something that we should be undertaking in the 21st century," said Anne Ruston, Australia's assistant minister for international development and the Pacific, on the sidelines of Monday's meetings. "The argument that we put forward from Australia is that we don't want to see any whales killed, whether they're killed because (of) commercial whaling or whether it's so-called scientific whaling."

The commission declared a "pause" to commercial whaling beginning in the 1985-1986 season, but it remains in place today. The killing of whales is allowed for research purposes, as in Japan's program, and for indigenous communities who practice subsistence hunting.

Australia says that non-lethal research techniques actually reveal more information about whales than can be learned through killing them. The United States also opposes lethal research hunts, but both countries support the exception for subsistence whalers.