The only thing surprising about this is that it took the US government so many years to finally implement this travel ban:
The Trump administration will ban American citizens from traveling to North Korea, U.S. officials said Friday, following the death of university student Otto Warmbier who died in June after falling into a coma in a North Korean prison.
Secretary of State Rex Tillerson had decided to impose “geographical travel restriction” for North Korea, the officials said, which would make it illegal to use U.S. passports to enter the country. They said the restriction would be published in the Federal Register next week and will take effect 30 days after that.
The officials were not authorized to publicly discuss the decision before it is announced and spoke on condition of anonymity. Two tour operators that organize group trips to North Korea said they had already been informed of the decision. [Associated Press]
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