China took aim at the United States and its expanding military alliances with Asian allies on Tuesday, saying that the security build-up was a threat to regional peace.

The US has pivoted its foreign policy towards Asia in recent years, alarming China and emboldening nations embroiled in maritime territorial spats with their giant neighbour, including Japan, the Philippines and Vietnam.

"Some countries are strengthening their Asia-Pacific military alliances, expanding military presence in the region, and frequently making the situation there tenser," China's defence ministry said in an annual white paper.

It did not name any particular nation, but in a press briefing at the launch of the report, defence ministry spokesman Colonel Yang Yujun made a thinly disguised swipe at US policy.

Asked whether Washington's influence was growing he said: "Certain efforts made to highlight the military agenda, enhance military deployment and also strengthen alliances are not in line with common interests and are not conducive to the upholding of peace and stability in the region."

The white paper on China's armed forces said that the nation "still faces multiple and complicated security threats and challenges".

It also accused "neighbouring countries" of complicating and exacerbating tensions, and explicitly targeted Japan for "making trouble over the Diaoyu islands".

The East China Sea islands are administered by Tokyo, which refers to them as the Senkaku, and have been the subject of a row between the two Asian powers that escalated dramatically last year after Japan nationalised some of them.

Both Beijing and Tokyo have in recent months scrambled fighter jets near the islands to assert their claims to the area -- a region where the seabed is believed to harbour valuable mineral reserves.

A Japanese foreign ministry official told AFP that Tokyo had protested to the Chinese embassy over the defence report. "China's peculiar argument about the issue is not acceptable," he said.

Yang said the paper revealed for the first time the strength of some units within the Chinese armed forces -- the world's largest active military.

He said the release of the document was aimed at "better introducing" the development of China's armed forces to a domestic and foreign public.

"China is very candid in terms of its strategic intentions," he said, adding: "We know that every country has its military secrets."

However, he did not explain why the declared fighting strength of 1,483,000 was markedly different from the 2,300,000-strong armed forces which most analysts claim Beijing commands.

US Secretary of State John Kerry visited Beijing last weekend as part of an Asia tour, and met with China's new leader Xi Jinping who hailed the relationship as "at a new historical stage".

But in a commentary issued shortly after, China's official Xinhua news agency said America's strategic "pivot to Asia" could breed mistrust, and Washington should "help seek reasonable and workable solutions to regional issues".

Beijing has repeatedly asserted that it does not seek an expansionist policy as it continues its "peaceful rise".

But it has boosted its declared military spending in recent years, and last month announced the latest in a series of double-digit rises, with a 10.7 percent increase last month.

China's military has undergone rapid modernisation in recent years. Last year the navy took delivery of its first aircraft carrier, the Liaoning, and it has also developed stealth fighter and anti-satellite capabilities.