TOKYO- Japan's Chief Cabinet Secretary Yoshihide Suga stressed Monday the importance of securing US deterrence in Asia, following media reports that a US Navy strike group will be moving toward the western Pacific near the Korean Peninsula.

"It is important to secure the deterrence power of the United States at a time when the security environment in the region is becoming increasingly severe," Suga told a news conference. "We want to strengthen deterrence and response capability further under the Japan-US alliance."

According to media reports in the United States, the USS Carl Vinson strike group, led by a nuclear-powered aircraft carrier, will make its way from Singapore toward the Korean Peninsula due to concern over a series of North Korea's missile launches.

Meanwhile in Naha, Four Chinese coast guard ships entered Japanese territorial waters near the Senkaku Islands in the southernmost Japan prefecture of Okinawa on Monday.

It was the first intrusion into the Japanese waters by Chinese government ships since March 28 and the ninth this year.

According to the Japan Coast Guard's 11th regional headquarters in Naha, the capital of Okinawa, the Haijing 2101, Haijing 2106, Haijing 2305 and Haijing 2306 crossed into the Japanese waters at a point north-northwest of Uotsurijima, the biggest of the Japanese-administered island group in the East China Sea, between around 10:15 a.m. (1:15 a.m. GMT) and 10:35 a.m.

The four ships left the waters at a point west-southwest of Uotsurijima between around 11:45 a.m. and 0:10 p.m.

The East China Sea islands are claimed by China, which calls them Diaoyu. (Jiji Press)