Photo/IllutrationThe Senkaku Islands in the East China Sea (Asahi Shimbun file photo)

Japan and China have agreed to begin operating a hotline to avoid accidental conflict in the East China Sea in another sign of improving ties between the two nations.

Several sources in the Japanese and Chinese governments said that an agreement in principle was made during discussions held in Shanghai on Dec. 5-6.

Shinzo Abe was in his first stint as prime minister in 2007 when the agreement was made with then-Chinese Premier Wen Jiabao to begin discussions for a direct communications link between the Self-Defense Forces and the Chinese military to avoid a clash in the waters and over the airspace of the East China Sea.

However, it has taken more than a decade to actually begin operating the hotline, mainly because of the negative fallout from Japan's purchase of the Senkaku Islands in the East China Sea in September 2012.

The continuing sensitivity of the Senkaku issue is still evident because no mention is made of those contentious islands in the agreement on the geographical limits of the hotline.

The actual operation of the hotline will begin after a formal agreement is made between the leaders of the two nations.

The warming of relations between Japan and China was given a major push forward when Abe met with Chinese President Xi Jinping in November, when they agreed to work to further improve ties.

The leaders agreed in 2014 to promote dialogue between the two sides on national security issues. While a general agreement had been reached on creating the hotline, as well as deciding on the radio frequency to be used in communicating in English, the final sticking point was on whether to include the Senkakus as part of the area covered.

Japanese officials were concerned that actually naming the islands as being part of the agreement would allow China to interpret that as a green light to have naval ships and military aircraft enter the waters and airspace around the Senkakus as long as prior notice was given.

Sources said an agreement was reached on beginning the hotline because Japanese officials became more confident that territorial claims by Japan would not be violated under the hotline agreement.

(This article was written by Nozomi Matsui in Tokyo and Takashi Funakoshi in Shanghai.)