(CNN)A possible parachuting of Adm. Harry Harris, the head of America's military in the Asia Pacific, as US envoy to South Korea shows President Donald Trump's administration is focusing all its effort and attention on the Korean Peninsula ahead of pivotal talks.
Trump's ambassador switch risks estranging Australia and angering China
But the potential nomination of Harris, who was previously pegged as the next Australia ambassador, risks antagonizing China and harming relations with their long-time ally in Canberra.
"This just gives ammunition for people on the anti-American or pro-China side of the debate (in Australia) to point to Washington and say this is an unreliable ally," Euan Graham, director of the International Security Program at Sydney's Lowy Institute, said.
Harris is a highly decorated naval commander whose nomination in February was seen as a sign of strength in the relationship between the US and Australia. However, hours before his confirmation hearing as Australian ambassador, the session was postponed until early May.
The White House has not confirmed the change of assignment, but Australian Prime Minister Malcolm Turnbull said he was told of the decision earlier this week.
"I'm disappointed Harry's not coming, because he's a really good friend and I think Harry will be disappointed he's not coming to Canberra too, because he loves Australia," Turnbull told CNN affiliate Sky News.
The decision comes just days before a historic summit between North Korean leader Kim Jong Un and South Korean President Moon Jae-in, and ahead of potential talks between Kim and US President Trump slated for late May or early June.
The admiral's appointment demonstrated the importance of the Korean Peninsula to the Trump administration, analysts said, and Seoul's urgent desire for a US representative.
"(But) it's unfortunate it has to come at the expense of Australia getting one. This shouldn't be a zero sum game. The US should be able to walk and chew gum at the same time," Robert Kelly, professor at Pusan National University's Department of Political Science, said.
The apparent choice of a high-profile military figure with close ties to the US government will be welcomed in Seoul, which has been without an ambassador for more than a year.
The post has been left vacant at a tense time on the peninsula, with a series of provocative nuclear and missile tests by North Korea last year and a concerted diplomatic outreach by South Korean President Moon.
Long-rumored candidate for the job, Victor Cha, was dropped from consideration in January after he publicly voiced concerns about a possible "bloody nose strike" on North Korea.
"South Korea want an ambassador who can speak for the President and interpret the President and explain things to the President," John Delury, a professor at Yonsei University's Graduate School of International Relations in Seoul, said.
At a Senate hearing in March, Harris said North Korea was the "most urgent security threat" to the United States in the Asia region, adding the shadow of Kim's nuclear capabilities "(loomed) over the American homeland."
The admiral said any military action by the United States in North Korea would not be quick or easy. "(But) we are ready to do the whole thing if ordered by the President," he said at the time.
Despite Harris' military pedigree and hawkish views, analysts said it was unlikely Pyongyang would be particularly concerned or shocked by Harris' appointment in Seoul.
Harris had previously said during a hearing of the Senate Armed Services Committee he was not "overly optimistic" about the outcome of a summit between Trump and Kim.
"(North Korea) is negotiating with the President himself at this point, that's pretty remarkable, so who the ambassador is ... that's less significant now," Kelly said.
One party that will be unhappy with the admiral's appointment to Seoul is the Chinese government, which has been a longtime critic of Harris.
Beijing has regularly been driven to fury by Harris' negative views on its actions in the Asia Pacific region, including the militarization of the South China Sea.
"China's intent is crystal clear. We ignore it at our peril," Harris said in public testimony in February. "I'm concerned China will now work to undermine the international rules-based order."
Two years earlier, the admiral denounced the China's island building program in the contested South China Sea, describing it as a "great wall of sand."
In 2016, China's Foreign Ministry spokesman Hong Lei accused Harris of "smearing" Beijing and "sowing discord" over his remarks on the South China Sea.
China's state news agency Xinhua also raised the question of whether the admiral's Japanese ancestry had influenced his views on China.
"Some may say an overemphasis on his background as a Japanese-American general is a bit unkind .. But to understand the Americans' sudden upgraded offensive in the South China Sea, it is simply impossible to ignore Admiral Harris' blood, background, political inclination and values," the February 2016 article said.
Despite Beijing's smears of Harris, it isn't clear whether they considered him more of a threat in Canberra or in Seoul. "It's hard to imagine Beijing being excited about it. But what are they going to do?" Delury said.
High-profile Australian leaders had been thrilled with the announcement of Harris' appointment in February. "Look forward to seeing you in Canberra, Harry," Turnbull said on his official Twitter at the time.
On Tuesday, Australian Foreign Minister Julie Bishop brushed aside the change of assignment saying "it's not unusual," and that Canberra understands the "significant challenges" facing the US on the Korean Peninsula.
Only opposition foreign affairs spokeswoman Penny Wong voiced any disapproval of the decision, saying it was "disappointing" the post of US ambassador to Australia had been left unfilled for 19 months.
The message from Washington to Canberra was clear in the admiral's reassignment, Graham said.
"The implicit assumption is that Australia won't put up too much of a fuss about it because they're basically on our side anyway, and I think that is a gross miscalculation of where the debate in Australia is," he said.
Australia's relationship with the United States has been under scrutiny domestically over the past decade, with some experts and leaders pushing for a more independent diplomatic policy and closer ties with an economically resurgent China.
Graham said the reassignment of Harris was a "unforced error" which made it more difficult for the Turnbull government to argue for closer US ties.
"The old days of assuming Australia can be taken for granted are no longer there and I think there will be a cost of (this decision)," he said.