March 9 (UPI) -- North Korea may have sold lithium-6, a type of lithium metal, to an overseas buyer, according to United Nations investigators.
Members of the U.N.'s Panel of Experts have issued a report that includes information on North Korea's weapons sales and the North Korea front company Green Pine Association Corp. that has been selling lithium online, The Wall Street Journal reported.
U.S. lawmakers briefed the State Department and intelligence agencies on the details of the report after being apprised of the information.
Green Pine makes missile systems, submarines and maritime military equipment, according to the report.
Lithium-6, also known as enriched lithium, can be used to make tritium, which makes nuclear explosions more powerful.
Tritium allows for the production of nuclear bombs with less required amounts of plutonium and uranium – and the small warheads they produce can be mounted on projectiles like intercontinental ballistic missiles capable of reaching the United States.
Lithium is also a dual-use element that can be used in batteries, lubricants and medicines. North Korea is believed to have abundant stockpiles of lithium stored in the country.
According to nuclear experts, the level of purity of the lithium sold could provide insight into the buyer's intentions.
Greg Jones, a defense expert at Rand Corp., said lithium enriched to 40 percent purity can be used to produce tritium, and higher levels can be used for fueling hydrogen bombs.
"It could be used for either, and neither is good," Jones said.
North Korea has conducted five nuclear tests since 2006.