Two U.S. defense officials have testified before Congress on China's military buildup and future potential.  VOA's Dan Robinson reports from Capitol Hill, questions from lawmakers on the House Armed Services Committee focused on the current capabilities of China's military and thinking about Beijing's long-term intentions.

James Shinn, Assistant Secretary of Defense for Asian and Pacific Security Affairs, says China has engaged in a sizable and sustained increase in defense spending, estimates of which range upward from an official figure of $60 billion.

Among other things, he says this has continued to shift the military balance in the Taiwan Straits in Beijing's favor, and places U.S. and allied forces in the region at risk.

At the same time the United States and its defense planners are in a position of not really knowing what China's true intentions are, particularly as much continues to be unclear about the Chinese buildup.

"This increasing capability may alter their intent.  In other words, the increasing capacity of the PLA [People's Liberation Army]  may present the Chinese leadership with more options, and as the chairman mentioned in his comments, this goes right to the heart of the issue what is the intent of this build up?," he said.

In the absence of more transparency on China's part, Shinn says the U.S. is forced to plan based on what it knows about China's expanding capabilities and, as he puts it, plan for the worst case.

China's buildup, he adds, has been across all of its military services, including nuclear forces, with heavy investment in what is called asymmetrical warfare and cyber capabilities.

Air force Major General Philip Breedlove, Vice Director for Strategic Plans and Policy on the U.S. military Joint Chiefs of Staff points to areas of progress, involving increasing numbers of military to military bilateral contacts.

Breedlove says these can help defuse potential situations in the Taiwan Straits, but he had this response when asked by one lawmaker about current U.S. thinking about China's intentions:

"It would be hard to construe an aircraft carrier as being a purely defense weapon.  I believe that one of the things we see China doing, like pursuing an aircraft carrier, like pursuing some of the longer range capabilities that they have, conventional capabilities, clearly indicate that they have aspirations beyond the shores of Taiwan," he said.

At the same time, Breedlove describes China has very pragmatic, focusing at present on making friends in oil-rich areas of the world, such as Africa, to ensure access to these areas.

Committee chairman Ike Skelton, a Democrat from Missouri, asserts that the focus of U.S. military resources on Iraq in recent years has allowed China to grow its influence in Asia and beyond.

While he points to some progress in terms of China's openness, such as providing access for U.S. officials to military facilities, Skelton had this observation: "China has still not adequately revealed its full defense spending, military modernization efforts, or its strategic intentions."

"Their military ambitions still remain clouded.  I and I know others on this committee as well as many others across the globe are concerned about their intentions, and as much about what we don't know as what we do know," said Representative John McHugh, ranking Republican on the committee.

As for recommendations, Shinn told lawmakers the U.S. must continue to build its intelligence and analysis, train and equip U.S. forces in the Asia-Pacific region, and work closely with allies so they can deal with enhanced Chinese capabilities.

Both officials declined to give detailed responses on certain questions citing the unclassified nature of Wednesday's committee hearing. However, the two subsequently took part in a classified closed-door session with lawmakers.