China's rapid military buildup changes the delicate balance of power in the Taiwan Strait, forcing the United States to adapt its military strategies, a top Pentagon official said overnight Thursday. Peter Rodman, the assistant US secretary of defense for international security policy, noted Thursday that China has more than 700 short-range ballistic missiles aimed at Taiwan, with numbers increasing at about 100 missiles a year. "When there are zero ballistic missiles opposite the Taiwan Strait, and a few years later there are 700, that's a change in the status quo," Rodman told reporters after testifying before the US-China Economic and Security Review Commission, an advisory panel created by Congress. "Our job is to maintain a military balance in the region, and we take our responsibility seriously." The United States opposes unilateral changes in the China-Taiwan relationship, Rodman said. But, he testified, China's "military buildup changes that status quo and requires us to adapt to the new situation, as we are doing." He did not elaborate.