SINGAPORE: US Secretary of Defence Pete Hegseth warned Saturday that China was "credibly preparing" to use military force to upend the balance of power in Asia, vowing the United States was "here to stay" in the Indo-Pacific region.

The Pentagon chief made the remarks at an annual security forum in Singapore as the administration of US President Donald Trump spars with Beijing on trade, technology and influence over strategic corners of the globe.

Since taking office in January, Trump has launched a trade war with China, sought to curb its access to key AI technologies and deepened security ties with allies such as the Philippines, which is engaged in escalating territorial disputes with Beijing.

"The threat China poses is real and it could be imminent," Hegseth said at the Shangri-La Dialogue attended by defence officials from around the world.

Beijing is "credibly preparing to potentially use military force to alter the balance of power in the Indo-Pacific", he added.

Hegseth warned the Chinese military was building the capabilities to invade Taiwan and "rehearsing for the real deal."

Beijing has ramped up military pressure on Taiwan and held multiple large-scale exercises around the island, often described as preparations for a blockade or invasion.

The United States was "reorienting toward deterring aggression by communist China", Hegseth said, calling on US allies and partners in Asia to swiftly upgrade their defences in the face of mounting threats.

Hegseth described China's conduct as a "wake-up call", accusing Beijing of endangering lives with cyber attacks, harassing its neighbours and "illegally seizing and militarising lands" in the South China Sea.

Beijing claims almost the entire disputed waterway, through which more than 60 percent of global maritime trade passes, despite an international ruling that its assertion has no merit.