US President George Bush’s choice to replace Donald Rumsfeld as defence secretary says China wants to peacefully take over rival Taiwan, but is boosting its military force in case of a war with the island.

Robert Gates, a former CIA director, said in written testimony submitted to the US Congress that the US must monitor China’s huge military growth, stand ready “to resist China’s use of force or coercion against Taiwan and assist Taipei in maintaining its self-defense.”

US military officials believe China’s military buildup is intended to back up threats to attack Taiwan, the self-ruled island that Beijing claims as its own territory. The two sides split in 1949 amid civil war.

China vows to keep the island from independence by force if necessary. The United States has pledged to provide Taiwan the means to defend itself.

Gates said that China, as it works toward its goal of becoming Asia’s pre-eminent power, is “expanding its political and economic influence in the region and generating options for military coercion.”

But China’s “near-term focus is on generating sufficient combat power to rapidly erode Taiwan’s will to resist and to deter or deny effective intervention in a cross-Strait conflict,” Gates said.

The US and China have recently co-operated on attempts to rid North Korea of nuclear weapons, and Gates praised Beijing for that, as well as for “improved behaviour on proliferation” and “increased transparency.”

But criticism of China far outweighs praise in Washington – including accusations that Beijing curbs its citizens’ freedoms, befriends energy-rich countries with questionable human rights records and encourages economic policies that lawmakers say cost American jobs.

Many also demand that China explain a military budget with an average annual growth rate Beijing puts at nearly 16% from 1994 to 2004. While China’s reported 2006 military budget is about 35 billion dollars, the Pentagon estimates the true scope of spending at as much as 105 billion dollars, which would make China the largest defense spender in Asia.

Chinese officials say they are open about military spending and have increased military exchanges with other countries.