The country's official news agency said the defecting soldier had become disillusioned with American "unequal society." Fews in the US believe this account.
North Korea said that US soldier Travis King bolted across the Korean border last month because he wanted to escape the "mistreatment and racial discrimination" suffered in the US military, as declared by the state news agency KCNA on Wednesday.
It was the first official confirmation that King is currently detained in Pyongyang, though the agency did not elaborate on his exact location.
The 23-year-old US soldier had served in South Korea, where he had been detained for nearly two months as a result of an altercation with a local, according to South Korean authorities. On July 18, he was escorted to Seoul's Incheon International Airport to fly home and face probable disciplinary action, but he never made it to his plane.
Instead, he joined a tour of the tightly controlled Joint Security Area (JSA) on the border between the two Koreas and sprinted into the North.
"According to an investigation by a competent organ of the DPRK (Democratic People's Republic of Korea), Travis King admitted to having entered the territory of the DPRK illegally," KCNA reported, using the official name of North Korea.
According to the agency, King "harboured ill feeling against inhuman maltreatment and racial discrimination within the U.S. Army" and wanted to stay in North Korea or a third country because he was "disillusioned at the unequal American society."
KCNA is a propaganda outlet and its content reflects the views of North Korea's leadership - including that the United States is an evil adversary. King's motivation to defect to North Korea remains officially unconfirmed.
"This is 100% North Korean propaganda in its element. King, as an American citizen held in North Korea, has no sway in how (North Korea) chooses to cast its narrative," said Soo Kim, an expert with Virginia-based consultancy LMI and a former CIA analyst.
"As for King's release, his fate rests in North Korea’s hands. Perhaps the regime will try to ‘bargain’ King’s life in exchange for financial concessions from the U.S. More than likely, negotiations won’t be easy, and terms will be dictated by Pyongyang," she said.
King's family said his mother, Claudine Gates, is appealing to North Korea to treat her son humanely.
"She's a mom worried about her son and would be grateful for a phone call from him," family spokesman Jonathan Franks said in the statement. "Lastly, she has been in touch with the Army this evening and appreciates a (Defence Department) statement that it remains focused on bringing Travis home."