CNN —  

When President Trump and North Korean leader Kim Jong Un held their historic talks Tuesday in a Singapore hotel, they weren’t in the room alone. Someone had to interpret for them.

That important task fell to State Department employee Lee Yun-hyang, who interpreted for Trump, and Kim Ju Song, a member of North Korea’s Foreign Ministry, who did the same for Kim.

What a crucial job they had. Interpreting at the diplomatic level can be the difference between finding peace or causing an international incident. Every word uttered by a world leader had to be interpreted and relayed to the other with exacting context and nuance.

Lee Yun-hyang
(President Trump’s interpreter)

Lee’s always wanted to use her voice, but not necessarily as an interpreter. She was originally a vocal music student in South Korea who got her start in interpretation work thanks to a friend, according to the Korea Times.

She also tried her hand at becoming a television producer, South Korean newspaper Chosun Ilbo reported, but her application was rejected because she was a woman. That was a clarifying moment for Lee, who then decided to leave the country.

“I cannot raise my daughter in a country that discriminates against women,” she told Chosun Ilbo.

Lee ended up in California in 1996 at the Monterey Institute of International Studies (now the Middlebury Institute of International Studies at Monterey), where she taught in the translation and interpretation program for eight years. From there, she joined the State Department for a couple of years, before returning to South Korea and working as a professor at Ewha Womans University in Seoul. She returned to the State Department in 2009.

She has interpreted for former Presidents Barack Obama and George W. Bush, as well as then-Secretary of State Hillary Clinton. She was also the South Korean interpreter at the 2010 Winter Olympics in Vancouver and at the 2008 Games in Beijing.

Kim Ju Song
(North Korean leader Kim’s interpreter)

Not as much is known about Kim Ju Song, the interpreter for the North Korean leader Kim. He was at the White House earlier this month when North Korean official Kim Yong Chol met with Trump, so he got a jump start in figuring out how to decode Trump’s speaking style.

He also interpreted for Kim Yong Chol when he went to South Korea for the Winter Olympics back in February, Chosun Ilbo reported.

Kim Ju Song reportedly has a high level of expertise in English.

“Even though he was not trained as a professional translator, he was picked up because of his outstanding English proficiency,” a defector who used to be a North Korean diplomat told Chosun Ilbo.

CORRECTION: An earlier version of the story incorrectly stated the name of the school where Lee Yun-hyang taught. The school’s name was the Monterey Institute of International Studies (now the Middlebury Institute of International Studies at Monterey).