General Charles Flynn, who commands more than 107,000 Pacific-based US Army personnel, said Chinese forces have made an "enormous amount of progress" in recent years.

"The trajectory that they have been following for the last decade, if I multiply that into the next decade, that is a concerning trajectory," the four-star general told AFP in a video interview from Hawaii on Wednesday.

Under Xi Jinping's decade-long rule, China's People's Liberation Army (PLA) has morphed from an ill-equipped and ineffective force into one of the world's fastest-growing and most potent.

Beijing also has the world's largest navy and a growing nuclear and ballistic arsenal, fuelled by a defence budget that is second only to that of the United States.

In March, China announced a 7.2 percent hike in military spending, building on a 7.1 percent increase the previous year.

At the time, outgoing premier Li Keqiang said "external attempts to suppress and contain China are escalating".

Flynn said China was forging a "formidable military instrument" at "a dangerous state of progress".

Tensions between Beijing and Washington have heightened in recent years, most notably over the issue of Taiwan. China considers the self-governed island part of its territory.

Washington and Beijing have also clashed over disputed Chinese claims in the South China Sea, and the pair have tussled for influence in the South Pacific.

Last month the United States published footage of a Chinese fighter plane flying to within three metres (10 feet) of an American B-52 bomber.

US officials said the Chinese aircraft had been travelling "with uncontrolled excessive speed... putting both aircraft in danger of a collision".

Chinese coast guard vessels have also rammed and used water cannons against Philippine boats in the country's exclusive economic zone.

The incidents were "irresponsible", "insidious" and "indicative of the way they are being more aggressive", Flynn said, referring to the PLA.

As part of its Asia-Pacific strategy, the United States has been trying to bolster its alliances in the region to counter China's "bullying" of its smaller neighbours.

Flynn insisted the United States would remain committed to the Pacific despite massive spending on the wars in Ukraine and Gaza.

He said he is "comfortable with the assets I have available and what the service is providing to me", adding that his approach would "continue on the path that we have designed over the last couple of years".

"I wake up every day knowing that there are wars in other parts of the world and we don't need another war," he said.