North Korea is undergoing a flurry of activity around the holidays, but predictably not of the merry variety: "There is activity at a number of locations indicating that North Korea is laying the groundwork for an expansion of their ICBM program—more systems, more buildings, more capabilities," Jeffrey Lewis, director of the East Asia Nonproliferation Program at the Middlebury Institute of International Studies, tells NBC News. Satellite images show that a temporary structure has been built at North Korea's Pyongsong site to accommodate a launcher arm; that gives credence to the North's threat of a "Christmas gift" missile launch. Senior American military leaders tell CNN that the US is prepared for any strike Pyongyang might launch. Meanwhile, the AP notes that Kim Jong Un on Sunday convened a ruling party meeting to decide on next steps to bolster the country's military. (More North Korea stories.)