Another alarming North Korea development: The country tried to sell a key material for fueling nuclear weapons to unidentified international buyers last year, according to a United Nations report. UN investigators say the material a state-owned company tried to sell online was lithium-6, which experts say can be used to produce tritium, a material that boosts the power of nuclear detonations, or to directly fuel nuclear bombs. "It could be used for either, and neither is good," Rand Corp. nuclear expert Greg Jones tells the Wall Street Journal. The company, Green Pine, is listed by the UN as Pyongyang's "primary arms dealer and main exporter of goods and equipment related to ballistic missiles and conventional weapons."
North Korea is naturally rich in the material and while it does have plenty of non-military uses, analysts say both the purity and the amount of the lithium-6 the state-owned company was trying to sell suggest it was intended for use in fission devices. Officials say the attempted sale has created more unease in the Trump administration about North Korea's nuclear program. After China described the US and North Korea as bound for a "head-on collision" on Wednesday, US Ambassador to the UN Nikki Haley said the US will have to see "positive action" from Pyongyang before talks can begin, Voice of America reports. (Read more North Korea stories.)