Japan and Taiwan have sealed a fishing agreement for the seas around disputed islands at the heart of bitter maritime row between Tokyo and Beijing.

The agreement, which was signed in Taipei on Wednesday after a four-year delay, will allow Taiwanese fishermen to fish in Japan’s exclusive economic zone around the Japanese-controlled islands in the East China Sea.

Under the deal, Tokyo and Taipei will designate an area in Japan’s claimed EEZ as jointly managed waters where fishing by both Japanese and Taiwanese boats will be allowed, reports Kyodo News agency.

The jointly managed waters will be defined by the geographic latitude-longitude system, according to the official Central News Agency in Taipei.

“The adoption of latitude-longitude system to replace the term ’12 nautical miles’ is a very smart move that avoids territorial controversies,” said Professor Fu Kuen-chen, a Taiwanese expert in maritime law.

The accord caused unease in China.

Its Foreign Ministry said Beijing was “extremely concerned” and hoped Japan “earnestly abide by its promises on the Taiwan issue and act cautiously and appropriately.”

Japan has diplomatic ties only with Beijing and recognizes Taiwan as belonging to China. Analysts said Japan aims to use the cross-strait issue to counterbalance China, reports South China Morning Post.