You can go to North Korea. However, the State Department has some advice.
The State Department has recommended that American citizens get a will, make funeral plans and get a power of attorney before visiting North Korea, according to Fox Newsin "Visiting North Korea? Draft a will and make funeral plans, State Department says."
Traveling to countries other than North Korea is likely not nearly as dangerous. However, this is good advice before traveling to any foreign nation.
Before leaving on an overseas trip, it is a good idea to have an estate plan in place.
Having powers of attorney drafted is an especially good idea, in case anything does happen, so someone back home can handle all of your affairs.
It is unlikely anything will happen to you on your next vacation, but it is always good to be prepared.
An estate planning attorney can advise you on creating an estate plan that fits your unique circumstances, including a visit to a foreign country.
Reference: Fox News (Jan. 15, 2018) "Visiting North Korea? Draft a will and make funeral plans, State Department says."