A portrait of American soldier Travis King is displayed as his grandfather, Carl Gates, talks about his grandson, July 19, 2023. (AP)

The United States has officially requested that the Democratic People's Republic of Korea (DPRK) returns Private Travis King, a US soldier who defected to Pyongyang, the US Department of State Spokesperson Matthew Miller told reporters.

"We have relayed messages to the DPRK that Private King crossed on his own and we want him returned safely," Miller said. The spokesperson also said Washington asked for information on the Private's health.

According to US military officials, King "willfully and without authorization" crossed over during a civilian tour of the Joint Security Area, which is a demilitarized zone that has separated the two Koreas since the end of the Korean War in 1953.

The #US Army has identified the soldier who crossed the demarcation line into #NorthKorea as Private (#Pvt) #TravisKing on Tuesday.
Here's what you need to know about the issue so far. pic.twitter.com/NxIQ2aJjnu
— Al Mayadeen English (@MayadeenEnglish) July 20, 2023

King, a cavalry scout who joined the military in January 2021, was assigned to the 6th Squadron, 1st Cavalry Regiment, 1st Brigade Combat Team, 1st Armored Division out of Fort Bliss, Texas, at the time of his duty in South Korea, as per Army spokesperson Bryce Dubee.

In a statement, the US Forces Korea Spokesperson Col. Isaac Taylor said, "We believe he is currently in [Democratic People’s Republic of Korea] custody and are working with our [Korean People’s Army] counterparts to resolve this incident."

However, reports say the DPRK has not yet responded to the US requests as tensions grow between the two countries after the US docked a nuclear-capable submarine in Busan port on July 18.