The travel ban comes as the Trump administration searches for more effective ways to ramp up pressure on North Korea over its nuclear weapons program.
"North Korea doesn't do anything out of the kindness of their hearts".
How did the news come to light?
He said the embassy was trying to check on the number of U.S. tourists left in the country. There was no official confirmation from the US.
It is estimated that 1,000 United States citizens travel to North Korea annually.
What form will the ban take? In June, he was freed from North Korea in a coma and died a week later in the U.S. Young Pioneer Tours announced the next day it would stop taking U.S. citizens on tours to Pyongyang.
"Due to mounting concerns over the serious risk of arrest and long-term detention under North Korea's system of law enforcement, the secretary has authorised a Geographical Travel Restriction on all U.S. citizen nationals' use of a passport to travel in, through, or to North Korea", Nauert said.
But Miyagi said the public should simply liken the preparation for a doomsday to the work being done to prepare for a hurricane and tsunami.
How have the travel agencies reacted?
Koryo issued a similar statement, saying that after the ban takes effect, "it will no longer be legal for anyone travelling on a USA passport to visit the DPRK as a tourist".
Tropical Storm Don forms east of Barbados
A Monday morning release said an Air Force Reserve aircraft was being sent to investigate the disturbance Monday afternoon. Although the storm is expected to die out by Tuesday, tropical storm warnings have been issued for Barbados, Grenada, St.
Mr Cockerell added: "It's unfortunate for the industry but also for North Koreans who want to know what Americans are really like".
South Korea's proposed military talks aimed at easing tension between the two Koreas planned for Friday failed to happen after the North snubbed the call, a setback for new President Moon Jae-in's hopes for dialogue.
North Korea allows foreign tourists to visit but their travel is strictly limited.
Reacting to it, the United States had then said that it was an ICBM with an estimated range of 5,500 kilometers and capable of hitting Alaska.
Neither the USA government nor the Swedish Embassy in Pyongyang have issued official statements about a ban.
The State Department said it will publish a notice in the Federal Register sometime next week, and the ban will take effect 30 days after.
How many Americans will it affect?
Westerners make up five per cent of total visitors, Americans about 20 per cent of the Western contingent, according to statistics.
The report, based on interviews conducted over a period of two years with 375 defectors from the isolated dictatorship, states that these executions, often extrajudicial, are done on river banks, schoolyards and marketplaces.
In recent years, tour companies have reported that roughly 800 to 1,200 Americans have visited North Korea annually.
What happened to Otto Warmbier?
Warmbier was arrested at Pyongyang airport in January 2016 for allegedly taking a propaganda poster from his hotel room, where he had been staying as part of an organised tour. Japan says North Korea has also detained at least several dozen of its nationals.
His family rejected North Korea's version of events, saying he had been subjected to "awful torturous mistreatment".