Washington: Kim Yong-chol, the septuagenarian former spy chief who held talks with US Secretary of State Mike Pompeo in New York on Thursday, is the ultimate North Korean regime insider.

Kim has been a border guard in the Korean demilitarised zone, a liaison officer with the United Nations, and a member of the team who held breakthrough negotiations with the South Koreans in the early 1990s. Over the past decade he was promoted to four-star general, and made head of the main North Korean intelligence service, known as the reconnaissance general bureau (RGB).

He has served three generations of the Kim dynasty and in recent months emerged one of the most powerful figures in Kim Jong-un’s regime, second only to the leader’s sister, Kim Yo-jong. He is vice-chair of the ruling Workers party and head of the section charged with dealing with the South. He was part of the North Korean delegation for the Winter Olympics closing ceremony, and he was at the leader’s side for meetings with the South Korean president Moon Jae-in and Pompeo .

“He wears several hats,” said Duyeon Kim, a visiting senior research fellow at the Korean Peninsula Future Forum thinktank. “He is extremely well versed in denuclearisation matters, and seems to have secured himself a spot in Kim Jong-un’s inner circle.”

To travel to the US, Kim had to be given a waiver from sanctions. He was head of the RGB from 2009 to 2016 during the time the spy agency is believed responsible for the 2010 torpedoing of a South Korean naval vessel, the Cheonan , in which 46 sailors were killed; and the 2014 hacking attack against Sony .

“Some people who met him early in his career describe him as brilliant, alert and receptive,” said Robert Carlin, a former CIA expert on North Korea, now at the Centre for International Security and Cooperation at Stanford University. “Others who dealt with him later in life say he is really stiff-necked who looks down on his interlocutors. Maybe he changes according to who is talking to.”

Kim Yong-chol is the highest-ranking North Korean official to visit the US since vice-marshal Jo Myong-rok in 2000. But it is unclear who decided the former spy chief should not fly to the capital, though the state department spokeswoman, Heather Nauert, suggested that the reason could be related to the different kind of sanctions waivers necessary for a trip to Washington. “I believe that if anyone were to travel beyond New York that they would need additional waivers for that, or they would need some sort of an approval for that,” Nauert said.

The fact that Kim has flown to the US at all, in only the second such high-level visit since the Korean war, suggests the issue at hand is a question that has to be resolved before there can be a summit in Singapore.

NBC news quoted US officials as saying a new intelligence assessment advised that the regime in Pyongyang had no intention of dismantling its nuclear arsenal in the near future. However, the officials told NBC that Kim Jong-un was willing to open a western burger franchise in Pyongyang as a gesture of goodwill.