Japan said on Wednesday that it would withdraw from an international agreement and resume commercial whaling, a defiant move to prop up an industry that still has cultural significance there, despite plummeting demand for whale meat.

Yoshihide Suga, Japan’s chief cabinet secretary, said the country would leave the International Whaling Commission, which established a moratorium on hunting whales that took effect in 1986.

The international agreement never stopped Japanese whaling, because it allowed the country to continue killing whales for scientific research while selling the meat. Critics considered the research a sham, little more than a cover for commercial whaling.

In recent years, Japan has had an annual quota in the Antarctic of 333 minke whales, which in the 2017-18 hunting season included 122 pregnant females. As part of its withdrawal from the international commission, Japan will stop its annual hunts in the Antarctic and limit whalers to its own waters. Commercial whaling will resume in July, Mr. Suga said.