China's state-run news agency on Thursday accused the United States of "interfering" after a Pentagon report warned that the Asian power's military was increasingly focused on naval power.

Xinhua said the annual Pentagon report to US Congress had drawn protest in the past over its "interfering nature" and "distortion of facts", although it welcomed recent improvements in military relations between the two powers.

"The 94-page report, as usual, interferes with the internal issue of China by making wilful comments on the situation across Taiwan Straits," Xinhua said.

China considers Taiwan, where the mainland's defeated nationalists fled in 1949, to be a province awaiting reunification, by force if necessary.

The Pentagon report released on Wednesday renewed US warnings that China was extending its military edge over Taiwan, citing better artillery that could strike targets within or even across the Taiwan Strait.

Xinhua also accused the Pentagon of "overlooking the country's peaceful defence policy" in its report, which said China's military was investing in high-tech weaponry that would extend its reach in the Pacific and beyond.

The weapons buildup comes as the Asian economic giant places a growing emphasis on securing strategic shipping lanes and mineral-rich areas in the South China Sea.

"The Pentagon report, submitted to the Congress by the Pentagon annually pursuant to a US law since 2000, has drawn protest from China over its interfering nature, distortion of facts and baseless speculations," the Xinhua report said.

"This year's report, however, said the United States recognises China's contributions that support a safe and secure global environment."

The dispute over Taiwan, including US arms sales to Taipei, has remained a stumbling block to Washington's attempts at promoting a security dialogue with the Chinese military.

However, Xinhua said relations between the US and Chinese militaries had improved over the past year.

It cited a visit to China last month by US Joint Chiefs of Staff Chairman Mike Mullen, America's top military official. Mullen's Chinese counterpart Chen Bingde visited the United States last year.