North Korean leader Kim Jong Un inspects a sub-unit under KPA Unit 1344 in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 9, 2016.

The State Department has issued an unusually severe warning to Americans considering traveling to North Korea, saying tourists to the authoritarian country may well be propping up its dangerous nuclear program.

"The [Democratic People's Republic of Korea] funnels revenue from a variety of sources to its nuclear and weapons programs, which it prioritizes above everything else, often at the expense of the well-being of its own people," according to the message dated Wednesday.