North Korea appears to be making new nuclear bomb fuel, satellite imagery shows, even as its leader, Kim Jong-un, has expressed willingness to negotiate atomic disarmament with President Trump.

Two separate teams of American analysts examining satellite images from January and February have concluded that the North’s reactor at Yongbyon, which had appeared to be dormant, is now making plutonium — a principal fuel of nuclear arms.

In a report this week, one of the teams, at 38 North, a research institute at the Johns Hopkins University School of Advanced International Studies, said rising plumes of steam from the reactor complex, as well as melted river ice nearby, suggested “the reactor is operating again” to make plutonium for the North’s nuclear weapons program.

The 38 North analyst team includes Frank V. Pabian, formerly a satellite image analyst at the Los Alamos National Laboratory in New Mexico, birthplace of the bomb.