China's military training this year will focus on "improving fighting capacity" to win "local wars", the defence ministry said Thursday, with Beijing embroiled in several territorial disputes.

The People's Liberation Army (PLA) has been tasked with improving its ability to "win battles" by President Xi Jinping, its commander-in-chief, who has also pushed a high-profile campaign to root out corruption in the world's biggest military.

"The PLA will firmly uphold the criteria of improving fighting capacity," defence ministry spokesman Senior Colonel Yang Yujun told reporters when asked about the military's exercise plans this year.

The army would also "take part in more joint exercise training and competition with foreign militaries so as to improve the capability of winning local wars", he said at a regular briefing.

Yang did not elaborate on the meaning of "local wars" but China has been involved in occasionally tense confrontations with Japan and the Philippines over maritime disputes in the East China Sea and South China Sea respectively, amid fears that the disputes could result in armed clashes.

Japan and China have long been at odds over the sovereignty of uninhabited islands in the East China Sea which Japan administers and calls the Senkakus but which China claims as the Diaoyus.

The countries previously agreed in principle to set up a maritime hotline in a bid to avoid clashes but further discussions were suspended after relations soured in 2012 when the Japanese government angered China by nationalising some of the islands.

Xi and Japanese Prime Minister Shinzo Abe in November held their first formal summit meeting on the heels of an agreement the two sides reached in an effort to paper over differences on the dispute.

Talks on the maritime issue subsequently resumed earlier this month in Tokyo, and Yang on Thursday reported progress.

He said that officials agreed, at China's suggestion, to change the system of communication to cover both sea and air.

"The change will facilitate the two sides to conduct exchanges and consultation on both maritime and air security issues," he said.

"Both sides agreed that the mechanism should be operative as early as possible since technical conditions for launching it have already been met," he added.

Asked separately about Chinese naval activities in the Indian Ocean, including submarines, Yang said that China has since 2008 been dispatching different types of ships to the Gulf of Aden to carry out escort duties and international anti-piracy operations.

"In the process we have notified relevant countries as to the escort missions of the PLA navy ships, including the PLA navy submarines," he said.

"These are quite normal activities and there is no need to read too much into them," he added.

China has been extending its naval reach, sending more vessels further away from its shores for operations including escort and anti-piracy missions, humanitarian assistance, disaster and medical relief, and search and rescue, Yang said.

"By doing so the Chinese navy is contributing to provide more international public service and is helping with peace and stability in the open seas," he said.