The United States has for the first time begun buying seafood from Japan to supply its military there, a response to China's ban on such products imposed after Tokyo released treated water from its crippled Fukushima No. 1 nuclear plant into the sea.

Unveiling the initiative in an interview on Monday, U.S. Ambassador to Japan Rahm Emanuel said Washington should also look more broadly into how it could help offset China's ban that he said was part of its "economic wars."

China, which had been the biggest buyer of Japanese seafood, says its ban is due to food safety fears.