SEOUL • United States President Donald Trump's decision to tap CIA director Mike Pompeo as his new secretary of state ahead of a historic US-North Korea summit signalled his intention to tighten his grip over North Korea policy, experts say.
It also sends a strong message to Pyongyang that the US means business and expects to see real progress on the denuclearisation issue when Mr Trump meets North Korean leader Kim Jong Un.
After all, Mr Pompeo is a hardliner who said in January that "we are not going to stand for allowing Kim Jong Un to hold Los Angeles, or Denver, or New York at risk".
At a forum held by the Foundation for Defence of Democracies last October, Mr Pompeo had this reply when asked what would happen if Mr Kim suddenly died: "If Kim Jong Un should vanish, given the history of the CIA, I am just not going to talk about it... Someone might think there was a coincidence."
Analysts said the decision to replace the more moderate Rex Tillerson with Mr Pompeo has increased the uncertainty and raised stakes for the planned Trump-Kim summit.
The US leader last week accepted an invitation to meet Mr Kim face to face by May, in a surprising turn of events following a year of tensions heightened by the North's nuclear and missile tests.
Mr Trump's shake-up of his team shows that he wants to be well-prepared for the summit with Mr Kim, said Professor Kim Yeon Chul of Inje University.
Some experts say Mr Trump may have selected Mr Pompeo because the latter has played a key role in creating the current mood for dialogue.
Since early this year, Mr Pompeo and South Korea's National Intelligence Service director Suh Hoon have had close communications, and even tried to mediate a meeting between US Vice-President Mike Pence and Mr Kim's sister at the Winter Olympics last month, although it was cancelled at the last minute.
In an interview with Fox News to explain Mr Trump's surprise decision to meet Mr Kim, Mr Pompeo said: "President Trump isn't doing this (the planned summit) for theatre. He is going to solve a problem.
"No mistake about it. While these negotiations are going on, there will be no concessions to make."
Some analysts believe that Mr Pompeo would make a good negotiator as he has Mr Trump's ear and could even help engineer bold progress in talks with North Korea.
But others say there is now a higher chance of the use of a military option against the reclusive regime if talks fall through.
"Despite a change of mood towards dialogue, (the replacement) seems to make it clear that denuclearisation is the only reason for Trump to meet the North Korean leader," said Mr Park Jeong Jin, vice-director of the Institute for Far Eastern Studies.
"Should things fall apart due to lack of the North's commitment to denuclearisation, the US appears to be dangling a veiled threat that military options remain on the table," he told Yonhap news agency.
Professor Park Won Gon of Handong University told the Korea Herald: "His pick of Pompeo shows that he wants to become the ultimate decider... What is scarier than appointing a hardliner (Pompeo) as a top diplomat is that there is no one around Trump who can criticise his policies."
Mr Mintaro Oba, a former Korea Desk Officer at the State Department, wrote in NK News that "it will take a concerted effort from all of us - Congress, our allies, think-tanks and the public - to hold the Trump administration accountable in the post-Tillerson era - and curb its worst instincts".