The United States government is banning citizens from traveling to North Korea.

Koryo Tours said the ban would be announced on July 27 and would go into effect 30 days later.

It said the Swedish embassy in Pyongyang, which handles consular affairs for the United States in the North, informed it of the ban, but did not say how long it would last.

US officials said that Secretary of State Rex Tillerson had decided to implement a 'geographical travel restriction' for North Korea, which would make the use of US passports to enter the country illegal.

Two tourist agencies that operate tours to North Korea said on Friday the U.S. government will soon ban its citizens from travelling to the North. Pictured, North Korean leader Kim Jong-Un

Young Pioneer Tours said in a statement: 'We have just been informed that the US government will no longer be allowing US citizens to travel to the DPRK'

'But it does seem to be the case that in just over a month, it will be impossible for Americans to visit as tourists,' said Koryo Tours general manager Simon Cockrell.

Another tour operator, Young Pioneer Tours, said on its website that it had also been informed of the ban, citing the same date.

Young Pioneer Tours said in a statement: 'We have just been informed that the US government will no longer be allowing US citizens to travel to the DPRK (North Korea).

'It is expected that the ban will come into force within 30 days of July 27th.

'After the 30 day grace period any US national that travels to North Korea will have their passport invalidated by their government.

'We will update further as more information becomes available.'

Koryo Tours said the ban would be announced on July 27 and would go into effect 30 days later. Pictured, US president Donald Trump

The statement said: 'After the 30 day grace period any US national that travels to North Korea will have their passport invalidated by their government'

Young Pionner was the agency that took U.S. student Otto Warmbier to North Korea. He was subsequently arrested there and sentenced to 15 years of hard labour.

Otto Warmbier, however, died six days after being brought back to the United States in a coma from North Korea.

The 22-year-old was returned to his family in Cincinnati, Ohio, on June 13 after spending 17 months in North Korea where he was arrested as a student for stealing a propaganda poster in January 2016.

He returned in a vegetative state, unable to communicate with his family and with devastating brain loss.

Young Pionner was the agency that took U.S. student Otto Warmbier (pictured) to North Korea. He was subsequently arrested there and sentenced to 15 years of hard labour

The 22-year-old was carried off a private plane last week after touching down in Cincinnati to be reunited with his family 17 months after he was jailed. He returned in an almost vegetative state and had suffered extensive brain loss

North Korean authorities dubiously blamed his condition on a bout of food poisoning which they said he suffered while imprisoned and released him on 'humanitarian grounds'.

His family announced his death, laying the blame for it squarely with Kim Jong Un and his regime.

'The awful torturous mistreatment our son received at the hands of North Koreans ensured that no other outcome was possible beyond the sad one we experienced today,' Fred and Cindy Warmbier said in a statement.

President Trump shared his condolences with the family immediately, describing their son as 'North Korea's latest victim'.

'When Otto returned to Cincinnati late on June 13th, he was unable to speak, unable to see and unable to react to verbal commands.

'He looked very uncomfortable - almost anguished. Although we would never hear his voice again, within a day the countenance on his face changed - he was at peace. He was home and we believe he could sense that.

'We thank everyone around the world who has kept him and our family in their thoughts and prayers. We are at peace and at home too,' they said.

Otto was a student at the University of Virginia when he traveled in a group to Pyongyang.

As he attempted to leave the country to return home on January 2, he was arrested and detained at the airport.

Upon his release, North Korean officials blamed his condition on botulism - a severe form of food poisoning which they said he contracted while in their custody.

The man's father rejected the claim, blaming his almost vegetative state on how it treated him.

'There's no excuse for the way the North Koreans treated our son and the way they have treated so many others,' Fred Warmbier fumed.