Admiral Harry Harris, America’s top military commander in the Asia-Pacific and an outspoken critic of China, appears set to be the next US Ambassador to Australia.

The US Pacific Commander has been offered the job, the Washington Post reported on Sunday (local time).

The report comes a day after US President Donald Trump met with Admiral Harris in Hawaii on a stopover ahead of the President’s crucial Asian trip with stops in Japan, South Korea, China, Vietnam and the Philippines.

“I’m a great admirer of Admiral Harris and I know he cares deeply about the Australian relationship,” former US ambassador to Australia Jeffrey Bleich told AAP.

The US has not had an ambassador in Canberra for almost a year and consternation has grown in US and Australian political circles about Mr Trump’s failure to fill the vacancy.

Admiral Harris fits in with the Trump administration’s increasingly hawkish approach to China, although the President is expected to walk a fine line on the Asian trip.

Mr Trump has talked about building his relationship with Chinese President Xi Jinping to encourage China’s continued help in halting North Korea’s nuclear and missile ambitions.

However, in Mr Trump’s much-anticipated speech at APEC in Vietnam later in the week he is expected to call out China on freedom of navigation in the South China Sea and other issues.

Admiral Harris in a recent video address to the Institute For Regional Security in Canberra said he had been “flattered by the warm response” to reports he was a candidate.

Admiral Harris has been a vocal opponent of China’s island-building in the South China Sea, dubbing it the “great wall of sand” to China’s chagrin.

His PACOM post is expected to end next year.

The admiral is viewed as an ideal person to help the US build the “quad” or “democracy diamond” strategic alliance with Australia, Japan and India to combat China’s influence in the Indo-Pacific.

-AAP