Choe led a North Korean delegation that met with a group of American experts, headed by Suzanne DiMaggio — director of the U.S. think tank New America — in Oslo, Norway, earlier this week, according to South Korean diplomatic sources.

DiMaggio is known as an Iran specialist well-versed in the Obama administration‘s nuclear talks with the Middle Eastern nation. Thomas Pickering, former U.S. envoy to the U.N., and Robert Einhorn, U.S. State Department‘s former special adviser for nonproliferation and arms control, were also among the American experts‘ group.