China's military transformation has intensified in recent years as it acquires more advanced weaponry and technologies to conduct nuclear, space and cyber warfare, the Pentagon said Wednesday.
The Chinese military buildup poses troubling questions because Beijing has not clarified its intentions and does not publicly reveal all of its defence spending, the Pentagon annual report to Congress said.
"Much uncertainty surrounds China's future course, particularly regarding how its expanding military power might be used," the report said.
While China's capability to sustain military power at long distances remains limited, the development of "disruptive" technologies in the nuclear, space and cyber warfare sectors is altering the balance of military power in the Asia-Pacific region, the Pentagon said.
The People's Liberation Army is transforming from a massive army designed to fight long wars of attrition on its territory to a capability to fight and win short conflicts of high intensity outside its borders, the report said.
The Pentagon's report to Congress on the Chinese military comes after a confrontation between the US and Chinese navies in the South China Sea earlier this month. The two sides have traded blame for the March 8 incident that occurred when five Chinese ships approached a US Navy vessel.
The Pentagon accused the Chinese of harassing the American ship in international waters, while Beijing said the ship was operating illegally, dpa reported.
On Taiwan, the report said China has continued its short-range missile buildup to oppose the island that split from China following the communist civil war. China regards Taiwan as a rogue province and has threatened to use military force if Taipei formally declares independence.
"Chinas armed forces are rapidly developing coercive capabilities for the purpose of deterring Taiwans pursuit of de jure independence," the report said.
"These same capabilities could in the future be used to pressure Taiwan toward a settlement of the cross-Strait dispute on Beijings terms," the Pentagon said.