The government’s Fisheries Agency may ask importers to refrain from buying Pacific bluefin tuna from Mexico as much as possible to nudge that country to take steps against overfishing, although any such the request will be nonbinding.

The request, which sources revealed Saturday, would represent a rare move for Japan, the world’s largest consumer of tuna, in seeking to effectively manage the finite resource. It comes just as countries are convening a meeting from Monday in California of a regional tuna commission to discuss bluefin tuna fishing in the eastern Pacific.

At the meeting of the Inter-American Tropical Tuna Commission, participating countries are set to discuss Tokyo’s proposal to halve catches in the eastern Pacific of juvenile bluefin tuna weighing less than 30 kg.

It remains unclear whether the proposal will be adopted, as Mexico is said to be reluctant. Juvenile bluefin tuna thrive in large quantities in the waters off Mexico.

Japan, which may see fewer imports of bluefin tuna as a result of the request, hopes to win concessions from Mexico by taking a tough stance toward the country, according to the sources.

Mexico caught roughly 5,280 tons of juvenile bluefin tuna in the Pacific Ocean in 2012, roughly half the total catch of the fish in that region. Most was shipped to Japan, where demand for Mexican-caught tuna is strong because of its reasonable price.

At an international conference on control of bluefin tuna in the northern Pacific in September, Japan and other participating countries, such as South Korea, broadly agreed to halve catches of juvenile Pacific bluefin tuna from next year.