The lightning diplomacy between the U.S. and North Korea before next week’s historic summit has thrust a little-known CIA officer into an uncomfortably public role as a key intermediary in talks between the two adversaries.

After years working on North Korea at the Central Intelligence Agency, Andrew Kim has been thrust into the spotlight accompanying Secretary of State Mike Pompeo in key meetings with Pyongyang officials. He took part in President Donald Trump’s Oval Office meeting with a senior North Korean envoy last week and has helped prepare the president for his June 12 summit with Kim Jong Un in Singapore.

The unusual public role has given Kim, who was raised in South Korea, extraordinary influence over the administration’s approach to the summit and the North Korean nuclear threat more broadly. Just as Pompeo has become Trump’s right-hand man on the Korea talks, twice meeting with Kim Jong Un this year, Andrew Kim has found himself in a similar role for the secretary of state.

“He is in effect the connective tissue right now across the dialogues with the North Koreans,” said Rexon Ryu, a partner at the Asia Group and former White House official and Pentagon chief of staff. “I wouldn’t be surprised if the reality is Andy is perhaps the most influential player right now.”

Kim so far has been seen, but not heard, in his new role. But according to half a dozen people who have followed his work, he has been involved in almost all levels of the government strategy toward North Korea. His elevation has pushed seasoned diplomats and policymakers to the sidelines, an unusual move that breaks with decades of precedent in confronting North Korea’s nuclear threat.

As a fluent Korean speaker who became the CIA’s station chief in Seoul, he gained the trust of senior officials on both sides of the border. Since returning to Washington, he has also had access to the secretive channel that the CIA maintained with Pyongyang during the Obama and Trump administrations.

Kim first gained public attention when North Korean state media ran a photograph of him in Pompeo’s meeting with Kim Jong Un in May. An Associated Press photograph was later disseminated showing him on the tarmac when Pompeo landed in Pyongyang on that trip.

Another photo, taken at a dinner Pompeo and his party had with North Korean officials on the same visit, shows Kim sitting at a table laden with food, right next to Kim Yong Chol, the top adviser to Kim Jong Un who would later meet Pompeo and then Trump in New York and Washington.

A Trump administration official who asked not to be identified discussing Kim said the CIA agent had used his Korean language skills during Pompeo’s meetings to make sure that North Korean translators were accurately conveying messages between Pompeo and the North Korean leaders. But the official emphasized that Kim has done far more than serve as translator, using his decades of knowledge to help the administration divine North Korea’s intent heading into the Singapore summit.

The CIA declined to make Kim available for an interview and refused to discuss any details of his history beyond describing him as a veteran. Likewise, several people who know Kim refused to talk about him given the secret nature of his work and the tenuous state of the negotiations with North Korea.

James Clapper, the former director of national intelligence in the Obama administration, waved off questions about Kim during an interview in Washington earlier this week, then relented just a bit.

“He’s excellent, he’s really excellent,” Clapper said. “He’s very realistic about North Korea.”

Born in South Korea, Kim briefly attended the prestigious Seoul High School, alma mater of the current head of South Korea’s national intelligence service, Suh Hoon, according to one of the people who knows him. He is also a relative of Chung Eui-yong, the South Korean national security adviser. The newspaper Chosun Ilbo reported in March that Chung is a cousin of Kim’s mother.

Kim had spent a career in the agency and retired after working as station chief in Seoul. He was then brought back to lead the Korea Mission Center, a body that Pompeo set up in May 2017 when he was still CIA director. According to a person familiar with Kim’s role, Pompeo picked Kim with the advice of his deputy at the time, Gina Haspel. Haspel now leads the CIA after Pompeo’s move to the State Department.

Since his public outing, Kim has taken on revered status in the Korean media, drawing attention in part for his gray hair. National broadcaster KBS said he’s come to be known as the “grim reaper” for what it described as his hawkish views.

Pompeo’s trust in Kim now extends so deeply that the secretary has included him in nearly all his meetings on the issue — whether with North Korean leaders or with Trump. He helped brief the president directly as the White House prepares for the Singapore summit and will join the U.S. delegation on the trip, according to one U.S. official.

According to people familiar with the intelligence community’s thinking on North Korea, Kim is likely taking a more skeptical tone to the North Korean government’s pronouncements, providing a counterbalance to a president who seems intent on making a deal regardless of the cost.

“The North Korean side regards diplomacy as war by other means,” said Nicholas Eberstadt of the American Enterprise Institute. “The North Korean government doesn’t do ‘win-win,’ it doesn’t do ‘getting to yes.”‘

Such a prominent role for an intelligence officer has raised eyebrows — even among former intelligence officers — given Kim’s lack of policy experience and the suddenly prominent role he’s playing at the very heart of the debate over policy.

“It does seem unusual,” said Bruce Klingner, the former CIA deputy division chief for Korea and now a fellow at the Heritage Foundation. “Just as the policy community isn’t supposed to infect the intelligence community, the intel community provides information to enable policy makers to make the best informed decisions possible but are not supposed to provide advice.”

Still, Klingner said Kim’s participation and deep knowledge of North Korea’s motivations could be invaluable. “We referred to North Korea as the hardest of the hard targets,” he said of his time in the CIA. “It’s extremely difficult to get good information.”