WASHINGTON -- China has begun initial deployment of a new ballistic missile capable of attacking U.S. aircraft carriers, according to a Pentagon assessment released on Monday.

The Dongfeng-21D is a precision-guided antiship weapon that the Defense Department sees as aimed at undercutting the U.S. ability to project naval power in the Asia-Pacific region.

“China is fielding a limited but growing number of conventionally armed, medium-range ballistic missiles, including the DF-21D,” reads the congressionally mandated annual report on China’s military capabilities. The missile gives the People’s Liberation Army “the capability to attack large ships, including aircraft carriers, in the western Pacific Ocean.”

The Defense Department report places the missile’s range at greater than 930 miles, though Chinese state media have said the missile can strike moving ships as far away as 1,700 miles.

David Helvey, deputy assistant secretary of Defense, told reporters that the missile fielding “implies a limited operational capability.”

It is not publicly known if a supporting network of Chinese satellites that would provide mid-course and terminal targeting guidance to the DF-21D in a possible attack is also in place. “I don’t have details on whether or not they have the entire architecture in place,” Helvey said. “It’s something that we’re watching very, very carefully.”

Helvey said he did not have publicly available information on how many of the missiles the U.S. military estimates are currently deployed or where they might be fielded.

“We’re concerned about … the ability of China to develop missiles that can project its military power with precision at great distances from China,” he said. “Obviously, something that can hold at risk large surface ships, including aircraft carriers, is something we pay attention to, but we put it in the context of a number of China’s military developments … that we characterize as anti-access and area-denial.”

The Pentagon report also noted that in the last year, the Chinese military “continued to improve capabilities in nuclear deterrence and long-range conventional strike.”

The PLA Second Artillery Corps, which oversees the nation's strategic nuclear force, “continues to modernize its nuclear forces by enhancing its silo-based intercontinental ballistic missiles and adding more survivable mobile delivery systems.”

The Asian power might be working on a new road-mobile ICBM with the capability of carrying more than one independently targeted re-entry vehicle, according to the DOD report.

China is also growing its sea-based nuclear deterrent with three Type 094 Jin-class ballistic missile submarines presently operational, according to the assessment.

Helvey noted the Chinese government’s announcement earlier this year that it would increase defense spending by 10.7 percent, which would bring its declared military budget to $114 billion. He added, however, that discerning the actual amount China spends on defense remains difficult, as Beijing does not include all defense expenditures in its declared military budget.

Last year, the United States and China made headway in their efforts to improve military-to-military contacts, with a number of high-profile visits by each side including trips by each country’s defense chief, according to Helvey.