North Korea has decided to expel a US citizen who illegally entered the country last month, Pyongyang's official KCNA news agency said Friday.

"While being questioned, he said he had illegally entered the country under the command of the US Central Intelligence Agency," KCNA said.

"Relevant authorities have decided to expel him from the country," it added.

A man with the same name was arrested in South Korea while trying to sneak over the inter-Korean border in November last year.

Byron, who is in his late 50s and from Louisiana, was later deported back to the US.

Media reports said he told South Korean officials he sought to facilitate talks between North Korea and the United States, although he is a private citizen.

It is rare for North Korea to release an American detainee so swiftly and it comes amid stalled negotiations over Pyongyang's nuclear programme.

"This gesture means the North wants to keep up momentum for dialogue with the US," professor Yang Moo-Jin at the University of North Korean Studies told AFP.

From journalists to missionaries, most Americans held by North Korea have been released after high-profile interventions.

The reclusive regime freed three US detainees in May in an apparent goodwill gesture before a summit between North Korean leader and US President Donald Trump in Singapore.

The three men travelled home with Secretary of State Mike Pompeo and were greeted by Trump on their arrival at an air base near Washington.

Currently, there are no known US detainees held by the rigid communist state. The latest release also came after fresh allegations emerged last month that Otto Warmbier, a US student who died after being held in the North, was tortured in custody.

The 22-year-old was jailed in the North for more than a year and was released in a comatose state in 2017 but died shortly after returning home.

The exact cause of his death remains unknown but a recent US media report claimed there was new evidence that he was beaten by the regime.

The director of the Pyongyang Friendship Hospital -- which treated Warmbier -- slammed the allegations as a "total distortion of the truth" in October.

North Korea has denied torturing Warmbier and claims he contracted botulism in detention.

At their historic Singapore summit, Trump and Kim signed a vaguely worded document on denuclearisation of the peninsula.

Progress has since stalled as Washington and Pyongyang spar over the meaning of the document.

Also on Friday, KCNA reported that Kim had overseen the testing of a "newly developed ultramodern tactical weapon".

It marked the first official report of a weapons test by North Korea since it began the delicate diplomatic process with Washington.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)