One of the most high-profile defectors from North Korea has spoken to foreign media for the first time, revealing that Pyongyang’s elite are turning against leader Kim Jong Un. Thae Yong Ho also predicted that reunification with South Korea could happen within five years, and warned U.S. President Donald Trump about the dangers of making a deal with the current regime over nuclear weapons.

Last August, Thae disappeared from North Korea’s embassy in London where he was serving as deputy ambassador, and promptly defected to South Korea. Thought to be the highest-ranking official ever to defect from the secretive country, Thae has given a series of interviews in recent days where he talks about sanctions, reunification, and the future of the country.

Here’s what we’ve learned about the secretive kingdom:

Thae, speaking to Reuters, said that there is a growing sense of “low-level dissent or criticism of the regime” which, until recently, was unthinkable but is now becoming louder. Thae was unequivocal in his view that for North Korea to prosper, everything needs to change. “We have to spray gasoline on North Korea, and let the North Korean people set fire to it.”

Thae ascribed the dissatisfaction among the country’s elite to what he called Kim’s “reign of terror,” which saw many of Thae’s colleagues purged as the dictator attempts to maintain absolute control. “The North Korean society is more than 70 years old, and if a society can only be maintained not by ideology or law but by the reign of terror, then the people do not trust the society,” Thae said.

In an interview with South Korean TV station Arirang, broadcast Tuesday, Thae said he believed that the lack of any natural successor to Kim means that when his reign ends — however that may come about — the country will fall and the process of reunification will begin. He told Arirang he believed this would happen within five years.

Asked about the possibility that Kim Jong Un’s brother – Kim Jong Chol – could take control, Thae told Reuters it was very unlikely. “Kim Jong Chol has no interest in politics. He is only interested in music. He’s only interested in Eric Clapton. If he was a normal man, I’m sure he’d be a very good professional guitarist.”

Thae told the BBC that while he, his wife, and their children are living safely in South Korea, he suspects that the family he left behind in North Korea will have been punished for his defection. “I am sure that my relatives and my brother’s and sister’s families by now are all sent to remote closed areas or prison camps. It really breaks my heart.”

Thae said the heartbreak of thinking about his family makes him “determined to do everything possible to pull down the North Korean regime.” He called on the international community to help bring about a reunification: “Korean reunification is not only a matter for Korean people but this is a matter for common prosperity for the whole of North East Asia,” he said. “Please join us together to reunify the country as soon as possible.”

North Korea is subject to U.N. sanctions over its nuclear and missile programs, and Thae has warned Trump and other world leaders about easing these sanctions in order to do any possible deals with Kim. Such a move would only serve to bolster North Korea’s insistence that it is a legitimate nuclear state, Thae said. “It seems very fine, his offer – and even some American experts agreed on this kind of approach – but if the American and South Korean government accept this kind of compromise deal, then it only serves to justify so far the stance of North Korean regime.”