China's military is seeking to improve its nuclear arsenal by acquiring more mobile ballistic missiles that could survive a possible attack, the Pentagon said Wednesday.

"China is modernizing its nuclear forces by adding more survivable delivery systems" and may be developing a new "road-mobile" ballistic missile, an annual report to Congress on Chinese military power said.

The improvements are "intended to ensure the viability of China's strategic deterrent in the face of continued advances" in the United States as well as, to a less extent, in Russia, it said.

State media have reported that China's Second Artillery Corps has carried out training exercises that emphasized camouflage and maneuver tactics, which the report said would be designed to "increase survivability" of the country's atomic arsenal.

China has consistently held to a "no first use" policy, saying it would use nuclear weapons only in response to a nuclear attack against China.

China focused on naval power: Pentagon
Washington (AFP) Aug 24, 2011 - China's military is increasingly focused on naval power and has invested in advanced weaponry that will extend its reach in the Pacific and beyond, the Pentagon said Wednesday.

China has pushed to develop anti-ship missiles that could strike aircraft carriers, improved its targeting radar, expanded its fleet of attack submarines and bolstered its fleet of warships, the Defense Department wrote in an annual report to Congress.

"The evolution of China's economic and geostrategic interests has fundamentally altered Beijing's view of maritime power," the report said.

The military buildup includes a new aircraft carrier, but the Pentagon played down its importance, saying it was a first step towards a future fleet of carriers expected to be built in coming years.

The carrier "will serve initially as a training and evaluation platform, and eventually offer a limited operational capability," it said.