Speaking to Fox News, Mr Kazianis said: “I think John Bolton is North Korea and China’s worst nightmare.
“He’s going to drive very hard terms when it comes to negotiations.
“He’s also going to drive hard terms in terms of trade, as you have been talking on for the last few segments.
Kim Jong-un reportedly made a secret visit to China’s capital Bejing on Tuesday in what is believed to be the leader’s first trip outside of the rogue nation since his ascent to power.
Speculation about a high-ranking official from Pyongyang visiting Beijing circulated on social media earlier today after Japan’s Kyodo News showed a North Korean train travelling into China.
Melissa Hanham, a researcher at the James Martin Center for Nonproliferation Studies, in Monterey, California, said: “Recent tensions and increased nuclear and missile capabilities mean China’s taking this seriously and doesn’t want to be left out of the process.”
North Korean expert Gordon Chang also said North Korea and China are “very concerned” by the hiring of former US ambassador to the UN John Bolton.
He said: “I think North Korea is very concerned that the United States is going to strike them.
“A bloody now or whatever, also I think that they understand that Bolton, with his proliferation security initiative, is going to cut off North Korea sales of weapons to, for instance, Iran.”
He added: “I’m sure the North Koreans are very concerned and also the Chinese because the Chinese have been aiding in this deadly trade and they’re not going to like to see Bolton in 1600 Pennsylvania put an end to their support for North Korea.”
President Donald Trump will reportedly meet the North Korean leader, and Mr Bolton said it is an opportunity to see if it just another ploy by Kim Jong-un to conceal the country’s nuke development.