An island outpost, one of several, being built by China in the South China Sea.

The world's second-largest economy may retaliate following Tokyo's decision to send a helicopter carrier to the South China Sea, potentially triggering a "tit-for-tat game at sea," Chinese state media has warned.

The Japanese vessel will patrol the disputed waterway and the Indian Ocean for two months beginning in September as part of Japan's efforts to promote a free and open Indo-Pacific, Reuters reported on Wednesday, citing officials.

That triggered a stinging rebuke from Chinese newspaper The Global Times the following day.

"Japan’s provocation is sure to negatively impact China-Japan relations," according to an English translation of a Global Times editorial by the official news website of China's military. "There will be the possibility that China may take some kind of countermeasures ... Tokyo knows perfectly well that China has the ability and means of retaliation, and it would not end well if the two countries launched a 'tit-for-tat' game at sea."