Choe is reportedly a regular participant in track 1.5 and track 2 diplomacy and has experience particularly in the area of North Korea–United States relations and nuclear issues. A statement by Choe released before the 2018 North Korea–United States Singapore Summit between Donald Trump and Kim Jong-un led to President Trump temporarily canceling the meeting. Choe had referred to US Vice President Mike Pence as a "political dummy", angering Trump. Regardless, Choe was a participant in the summit when it took place on 12 June. At the 2019 North Korea–United States Hanoi Summit, Choe made a last-minute attempt to reach an agreement with her American counterparts, but the talks failed to reach a deal.