Tokyo: Chinese vessels have intensified activities around Japan this week, sending a clear message of deterrence after Tokyo designated Beijing an unprecedented "strategic challenge" in its latest National Security Strategy, according to a report by Radio Free Asia (RFA).

Japan, on December 16, unveiled three defence-related documents. The documents named China as the main challenge to the region's security and stability and focused on ways for Japan to boost its "counter-strike capabilities."

"The Chinese Coast Guard said on WeChat that its ships patrolled "in the Chinese territorial waters surrounding the Diaoyu islands on Wednesday," using the Chinese name for the Senkaku islands which are under Japan's control but are also claimed by China," reported RFA.

Territorial waters fall within 12 nautical miles of island coasts.

Tokyo has often accused Beijing of violating its sovereignty over the Senkaku islands.

The Japanese Ministry of Defence Joint Staff in a press release on Wednesday said that the Chinese People's Liberation Army (PLA) Navy's aircraft carrier Liaoning and escorting warships have since December 16 been conducting drills in the West Pacific.

Between Saturday and Tuesday, the Liaoning hosted about 130 aircraft sorties while operating around Okidaito island and Kitadaito island in the south of Japan, the Japanese Ministry said, according to RFA.

Two Type-055 large missile destroyers and a number of other vessels are a part of the Liaoning carrier group.

Recently, Japan's Defense Ministry reported that a Chinese Navy Shupang-class survey ship sailed through Japan's territorial waters near Yakushima Island.

According to the Japan Ministry of Defense/Self-Defense Forces, on December 19, it was confirmed that a Chinese Navy Shupang-class survey ship sailed through Japan's territorial waters near Yakushima Island.

"This is the 9th time, the first since November this year, that we announce Chinese Naval vessel's entry into Japan's territorial waters," tweeted Japan Ministry of Defense/Self-Defense Forces.

The Ministry further added, "These Chinese naval activities are of national security concern. #JMOD/#JSDF resolutely protect Japan's territory, territorial waters, and airspace."

This show of force by the PLAN coincided with the release of a new National Security Strategy (NSS) by Japan on December 15, 2022. According to this new doctrine, Japan intends to acquire counter-attack capabilities.

"We live in the world of a historical inflection point and in the face of the most severe and complex security environment since the end of WWII," the new NNS outlines, referring to increased activities of North Korea, China and Russia in Japan's Area of Security.

"A key to deterring invasion against Japan is counterstrike capabilities that leverage stand-off defence capability and other capabilities," it added.

Japan is finding itself in the midst of the most severe and complex security environment since the end of WWII with mounting threats from China and North Korea.