The new restrictions, slated to go into effect on October 18, resulted from a review after President Donald Trump's original travel bans were challenged in court.
The addition of North Korea and Venezuela broadens the restrictions from the original, mostly Muslim-majority list.
"North Korea does not cooperate with the United States government in any respect and fails to satisfy all information-sharing requirements," a Trump administration proclamation said.
An administration official, briefing reporters on a conference call, acknowledged that the number of North Koreans traveling to the United States now was very low.