Japan was expected to launch its amphibious marine brigade on Tuesday in a move interpreted by local media as an attempt to counter maritime advances from China.

The rapid deployment brigade, affiliated to the Ground Self-Defense Force, will be based in Camp Ainoura in Sasebo, Nagasaki prefecture, and is supposed to defend Japan's southern outlying islands, according to the Asahi Shimbun.

Chen Hongbin, researcher at Shanghai Institutes for International Studies, said the deployment is clearly targeted at China's marine sovereignty.

Chen said Japan's recent military moves indicate that Prime Minister Shinzo Abe regards China as its "imaginary enemy".

Its national defense plan has been turned to a specific strategy targeting China, which will lead to deteriorating China-Japan relations and a dangerous situation in Northeast Asia's stability.

Liu Jiangyong, professor of International Relations at Tsinghua University, said dispersing the "China threat" has become a tactic for the Japanese government to increase its military power.

Abe is suffering falling trust because of the ongoing land-sale scandal, and Liu said that in order to gain public support for increasing military spending, the Abe administration is playing its "old trick" of establishing an overseas enemy.

An opinion poll by the Nikkei Shimbun and TV Tokyo on March 23-25 showed that approval ratings of Abe's cabinet had slumped to 42 percent from 56 percent in February.

Japan has decided to purchase 17 Ospreys from the US for the 2,100-strong new brigade to transport the marines to any potential island battlefield. The delivery of the aircraft is expected to begin in fiscal year 2018, which starts on April 1.

The Japanese government officially decided to establish the rapid deployment brigade, modeled after the US Marine Corps, in late 2013 to bolster the GSDF's amphibious capability to defend the Nansei island chain located between the island of Kyushu and Taiwan.

The developments come as Japan's ruling Liberal Democratic Party is pushing to rewrite the country's pacifist Constitution.

At its annual convention on Sunday, the LDP adopted a proposal to revise the Constitution in line with a plan floated last year by Abe, who is also the president of the LDP, to bolster the Self-Defense Forces.

Abe proposed last May that the first two clauses of Article 9, which renounces the right to wage war and bans maintenance of a standing military, be kept intact but that a reference to the SDF be added to clarify its status.

"Let's stipulate the Self-Defense Forces and put an end to a controversy about violation of the Constitution," Abe said.

On Sunday protesters in Tokyo called for stopping constitution revision and demanded Abe's resignation over a suspected cover-up in the cronyism scandal.