Pyongyang, the North Korean capital, in April.
Seoul - It took the decision due to "the serious and mounting risk of arrest and long-term detention of US citizens".
He had been convicted of offences against the state for trying to steal a propaganda poster from a Pyongyang hotel and sentenced to 15 years' hard labour, with President Donald Trump blaming Pyongyang's "brutal regime" for his plight.
On its website the State Department said it took the decision due to "the serious and mounting risk of arrest and long-term detention of US citizens".
Three Americans accused of various crimes against the state are behind bars in the North, which is engaged in a tense standoff with the Trump administration over its banned missile and nuclear weapons programmes.
Earlier this week Pyongyang launched a missile over Japan, in a major escalation, and it has threatened to fire rockets towards the US Pacific territory of Guam.
In July it carried out its first two successful tests of an intercontinental-range missile, apparently bringing much of the US mainland into range.
Exemptions to the travel ban are available for journalists, Red Cross representatives, those travelling for humanitarian purposes, or journeys the State Department deems to be in the national interest of the United States.
But NGOs working in the North privately express concerns about how the process will function and the potential impact on their work.
A few remaining US citizens in the country left on Thursday, reports said.
"It will do nothing other than surrender the opportunity of presenting to even a few local Koreans a more balanced and rounded portrayal of Americans counter to the official portrayal of Americans in national media - of demonic, rapacious wolves," he told AFP from Pyongyang.
"Any soft power advantage the US enjoyed through the decency of its citizens who travelled here has now been removed in a paternalistic and somewhat un-American act."
Norwegian artist Marius Engan Johansen and his North Korean counterpart Ri Pak sculpted clay busts of each other on either side of the same stand.