The department introduced the rules to prevent Americans from visiting the communist nation following the death of a US citizen, Otto Warmbier.

Violators may face criminal penalties and have their passports revoked.

Warmbier was arrested and jailed in 2016 after Pyongyang accused him of attempting to take a propaganda sign from a hotel while visiting there.

He was released in June last year, but he was in a coma. He died shortly after returning to his family in the US.

The ban was set to expire Friday, but it will be extended through Aug. 31, 2019. The measure will soon be published in the Federal Register.

It comes at a time when the Trump administration struggles to revitalize denuclearization negotiations with the North.

Pyongyang has refused to move the process forward, calling for additional rewards for its moratorium on nuclear and missile testing and the dismantlement of some related facilities.

It demands regime security assurances, including a declaration of an end to the 1950-53 Korean War.

Speaking about North Korea at a Washington forum earlier this week, US Ambassador to the United Nations Nikki Haley said, "We knew this was going to be a slow, tough process." (Yonhap)