North Korea could carry out an underground test of a nuclear weapon as early as Tuesday night as the North's reclusive leadership dramatically tries to up the stakes with the U.S. and the West, U.S. officials told NBC News.
U.S. officials say North Korea may already have an arsenal between 12 and a "few dozen" far more advanced weapons, many more than generally believed.
The officials couldn't be specific on a date for the test, but they told NBC News they were "100 percent" certain there would be a nuclear test within the next two weeks or "at any time."
Tensions between North and South Korea increased this week when Pyongyang threatened to turn Seoul into "ashes." While the North regularly issues such threats, the South seemed to be taking this round of threats more seriously by increasing its security.