SEOUL • Once rejected by North Korea as "human scum", US President Donald Trump's latest pick for national security adviser has called for regime change in North Korea, prompting worries in Asia ahead of a historic summit between Washington and Pyongyang.
Mr Trump announced in a tweet he was replacing General H.R. McMaster with Mr John Bolton, a former US ambassador to the United Nations who has advocated the use of military force against North Korea and Iran, and has previously been rejected as a negotiating partner by Pyongyang.
"This is worrisome news," said Mr Kim Hack Yong, conservative lawmaker and head of the national defence committee of South Korea's Parliament. "North Korea and the United States need to have dialogue, but this only fuels worries over whether the talks will ever happen."
At Seoul's presidential Blue House, which has been forced to navigate between the unpredictable personalities of leaders in both Pyongyang and Washington, officials were circumspect.
"Our stance is that if a new road opens, we have to go that path," a senior Blue House official who asked not to be named told reporters.
"Bolton has much knowledge on the issues regarding the Korean peninsula and most of all, we know him to be one of the US President's aides who is trusted."
He said South Korea's National Security Office head Chung Eui Yong had not yet spoken with Mr Bolton, and Mr Chung's reaction to Gen McMaster's dismissal was "not bad".
Mr Bolton had described Mr Trump's plan to meet North Korean leader Kim Jong Un as "diplomatic shock and awe", and said it would be an opportunity to deliver a threat of military action. The meeting is supposed to happen by the end of May, but an exact time and place have yet to be settled on.
Pyongyang had no immediate comment about Mr Bolton, whose criticism of then North Korean leader Kim Jong Il and Pyongyang's human rights record in 2003 spurred state media to call him "human scum and bloodsucker".
North Korean officials would not recognise him as a representative of the US government or talk with him because of his "political vulgarity and psychopathological condition", state media said at the time.
Mr Bolton's appointment came 10 days after Mr Trump fired Secretary of State Rex Tillerson, another moderating influence, replacing him with hawkish CIA director Mike Pompeo.
His appointment will further diminish hope for China and the US to see eye-to-eye on security issues, according to Dr Shi Yinhong, an expert on China-US relations at Renmin University in Beijing.
"What security cooperation with China can there be? Nuclear weapons, North Korea, Taiwan, South China Sea, cyberspace… Where is there hope for cooperation?" Dr Shi said.
"Trump and Xi Jinping have spoken in public of the logic of cooperation, but with the negative direction of trade and security cooperation, these words seem more and more empty."
Dr Zhao Tong, an expert on North Korea and nuclear disarmament at the Carnegie-Tsinghua Centre in Beijing, said Mr Bolton's previous calls for China to pursue regime change in North Korea, as well as for a reunification of the peninsula under the South Korean government, were "very unrealistic".
"His views on strategic security issues will reinforce the Chinese convictions that it needs to build up its hard power," Dr Zhao said.
Tokyo expressed hopes that communication with Washington would go on as normal, with one Japanese government official saying he was "very optimistic" Japan would be able to get along with Mr Bolton as he has many friends inside the Japanese government.
Professor Narushige Michishita at Tokyo's Graduate Institute for Policy Studies said Mr Bolton's toughness could present a hurdle in dealing with Pyongyang.
"The problem is that he doesn't have any flexibility. That is a negative concern that I have," Prof Michishita said.
Incoming US national security adviser John Bolton has been an active presence on TV and on Twitter. His recent tweets give some insight on what he will bring to the White House.
ON NORTH KOREA
It's important to stand behind our South Korean allies, but if we pay heed to the lessons of history, talking to #NorthKorea would be fruitless.
ON FEB 13
We have a very limited amount of time left before #NorthKorea gains deliverable nuclear weapons. We've got to look at the very unattractive choice of using military force to deny them that capability.
ON JAN 11
The recent Russian presidential election was a chance for #Putin to practise election meddling on his own elections so he can do it better elsewhere. We need a long term strategy to deal with countries like #Russia and #China with long standing rulers.
ON MARCH 20
The #Nato alliance must have a very strong response to the poisoning of a former #Russian spy in Great Britain. I am sure that is under consideration by @POTUS and his administration.
ON MARCH 19
There needs to be a strategic response to Russia's new nuclear missiles to show our allies in Europe that we will not let #Russia push the US or its allies around.
ON MARCH 2
The US must strengthen its allies in Central and Eastern Europe through #Nato and ensure that there are effective countermeasures to the cyber war that Russia is engaging.
ON FEB 20
Washington and its allies do not need more #Russian adventurism in #MiddleEast, especially given the Moscow-Teheran-Damascus-Hezbollah axis.
ON JAN 24
The #Irannucleardeal was a strategic mistake in 2015. This deal needs to be abrogated and America must craft a new reality that reflects the actions of the Iranian regime.
ON JAN 29
If the Iranian opposition is prepared to take outside support, the US should provide it to them.
ON JAN 5
ON THE MIDDLE EAST
The Middle East peace process has long needed clarity and an injection of reality, and Trump has provided it by making the decision to move the US embassy in #Israel to #Jerusalem.
ON DEC 14, 2017