Tokyo: Japan has lodged a protest to China over the longest ever presence of its ships in the Japanese territorial waters near the Senkaku islands, Japanese Chief Cabinet Secretary Hirokazu Matsuno said on Monday.

"On December 22, ships of China maritime authority entered our country's territorial waters near the Senkaku islands... On December 25, they left the territorial waters... The presence of Chinese ships in our territorial waters for 72 hours 45 minutes is unacceptable... A strong protest and a demand to immediately leave the territorial waters have been sent [to China] through diplomatic channels," Matsuno told a press conference.

The chief cabinet secretary noted that Chinese ships had entered Japan's waters 28 times this year.

The uninhabited islands have been a source of long-simmering tensions, with China arguing they have been a well-documented part of its territory for centuries.

Separately, Taiwan also claims the islands, saying Japan annexed them from its territory in 1895. The islands came under US control after WWII and were handed over to Japan in 1971.

(With UNI inputs)