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…

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.”…

At the high end of the range, U.S. officials and other researchers said, North Korea may already have up to “a few dozen” nuclear weapons that could be fitted atop its vast fleet of ballistic missiles. Currently, North Korean missiles are limited to an intermediate range, capable of hitting cities in Japan or South Korea but not the United States. What the new test could reveal is an improvement in the type of weapons North Korea has.