President Trump speaks on the phone with Australian Prime Minister Malcolm Turnbull in January 2017. (Alex Brandon/AP)

President Trump will nominate the top U.S. military commander overseeing the Asia-Pacific region as the next ambassador to Australia, the White House announced Friday.

Navy Adm. Harry B. Harris Jr. is completing a three-year assignment as head of U.S. Pacific Command, where his tough stance on North Korea and Chinese military adventurism drew notice and approval from the Trump administration. Australia is a plum diplomatic posting that sometimes goes to presidential donors or friends, but the post has been vacant since Trump's inauguration. Australia, a close ally, was increasingly concerned last year that the vacancy signaled a downgrade in relations.

Trump erupted in frustration during a phone call a year ago with Australian Prime Minister Malcolm Turnbull and later tweeted that an Obama-era agreement for U.S. resettlement of some refugees detained by Australia was a “dumb deal.”

The White House statement about Harris describes him as “a highly decorated, combat proven Naval officer with extensive knowledge, leadership and geo-political expertise in the Indo-Pacific region.”

Harris, 61, has been a strong voice within the military and among government policymakers for a confrontational stance against Chinese military expansion or aggression. He has warned about the dangers of ignoring or appearing to condone the Chinese militarization of artificial islands in the South China Sea, and he coined the term “Great Wall of Sand” to describe the Chinese effort to expand military influence.

The Chinese government has singled out Harris for criticism, and the official media have sometimes suggested that Harris may be biased toward Japan because his mother was Japanese.

“To understand the Americans' sudden upgraded offensive in the South China Sea, it is simply impossible to ignore Admiral Harris’s blood, background, political inclination and values,” the Xinhua News Agency once wrote.

Unlike many of Trump's nominees for ambassadorial posts, Harris is not expected to be subject to delay by Democrats. The blunt-spoken, wisecracking Navy officer has years of experience in the region and already holds a security clearance.

For the White House, it might not hurt that Harris has appeared to side with Trump over whether it is appropriate for NFL players to kneel instead of standing during the playing of the national anthem.

“You can bet that the men and women we honor today — and those who died that fateful morning 75 years ago — never took a knee and never failed to stand whenever they heard our national anthem being played,” Harris said at a Pearl Harbor commemoration in 2016.