U.S. Secretary of Defense Mark Esper delivered a pointed assessment of North Korea's weapons program on Friday: the country is "clearly" trying to build a long-range, nuclear-capable missile, he said.

It was an unusually candid public comment from a senior Trump administration official about the DPRK's specific intentions -- all the more so because President Trump has insisted in recent weeks that DPRK leader Kim Jong Un promised to give up his country's nuclear weapons.