North Korea has said US soldier Travis King crossed into its territory last month because of "inhuman maltreatment and racial discrimination" in the army.
The 23-year-old private dashed across the border from South Korea on 18 July while on a guided tour.
Private King admitted to crossing illegally and wanted refuge in the North, state news agency KCNA reported.
It is the first time Pyongyang has acknowledged detaining the soldier. The claims have not been verified.
They appeared in a statement which has so far only been published by the government-controlled KCNA. It did not provide further details about Private King's health or whether the country would accept him as a refugee.
Concerns have been growing for the welfare of the US soldier, who has not been heard from or seen since his crossing.
The US is trying to negotiate Private King's release with the help of the UN Command, which runs the border area, and has a direct phoneline to the North Korean army.
Responding to the North Korean report on Wednesday, a Pentagon official said the US could not verify the claims and its priority was to have Private King brought home safely "through all available channels".
North Korea has given no information on how it plans to treat Private King but said the soldier admitted he had "illegally" entered the country.
The fact that North Korea's statement emphasised Private King's illegal entry suggests that it is not thinking of having him stay even if he wants to, said Christopher Green, a senior consultant at the think-tank International Crisis Group.
"That is not surprising. He would lose all his political value to them if that were the case," said Mr Green, but added that North Korea is in no rush to negotiate Travis King's return to the US just yet.
"They have very publicly thrown in their lot with Beijing and Moscow, as high-level delegation visits from both countries to Pyongyang in recent weeks show. It is a mistake to think that North Korea is or needs to be in a hurry to deal with the Travis King mess," he said.
The statement on KCNA did not say if he would face prosecution or punishment, and there was no mention of his current whereabouts or condition.
"During the investigation, Travis King confessed that he had decided to come over to the DPRK [North Korea] as he harboured ill feeling against inhuman maltreatment and racial discrimination within the US Army," KCNA reported.
"He also expressed his willingness to seek refuge in the DPRK or a third country, saying that he was disillusioned at the unequal American society."
Private King is a reconnaissance specialist who has been in the army since January 2021 and was in South Korea as part of his rotation.
Before crossing the border, he served two months in detention in South Korea for assault charges and was released on 10 July.
He was supposed to fly back to the US to face disciplinary proceedings but managed to leave the airport and join a tour of the Demilitarised Zone (DMZ), which separates North and South Korea.
The DMZ, one of the most heavily fortified areas in the world, is filled with landmines, surrounded by electric and barbed wire fencing, and monitored by surveillance cameras. Armed guards are supposed to be on alert 24 hours a day although witnesses say there were no North Korean soldiers present when Private King ran over.
His family have previously told US media that he had relayed experiencing racism in the army. They also said his mental health appeared to have declined after he spent time in a South Korean jail.
"It feels like I'm in a big nightmare," said his mother Claudine Gates, adding the family was desperate for answers.
North Korea is one of the few countries still under nominally communist rule and has long been a highly secretive and isolated society.
Its government, led by Kim Jong-un, also stands accused of systematic human rights abuse.
Analysts say the detainment of Travis King has played into North Korea's anti-US messaging, at a time when relations between the two countries are their worst in years.
Pyongyang will most likely have relished the opportunity to highlight racism and other shortcomings in American society, especially given the international criticism it receives for human rights abuses.
The UN Security Council is due to hold a meeting on Thursday to discuss the human rights situation in North Korea for the first time since 2017.
Ahead of its comments on Travis King, North Korean media had put out a statement on the UN meeting, which will be led by the US.
"Not content with fostering racial discrimination and gun-related crimes, the US has imposed unethical human rights standards on other countries", it read.