An American diplomat said Thursday that the U.S. is "working very hard" to determine the status of U.S. Army Private Travis King, who remains held in North Korea days after crossing into the country during a tour of the DMZ. 

U.S. Special Envoy for North Korea Sung Kim made the remark during the opening of a trilateral meeting between the U.S., Japan and South Korea on countering North Korea’s threats, adding that officials also are working on "ensuring his safety and return," according to Reuters. 

North Korea has yet to comment on the matter. 

As of Wednesday, officials in their Korean People’s Army have yet to respond to the Pentagon either, the State Department says. 

US SOLDIER SPRINTED INTO NORTH KOREA, EYEWITNESS THOUGHT IT WAS A TIKTOK ’STUNT’ 

Tourists stand near a border station at Panmunjom in the DMZ between South and North Korea

A group of tourists stands near a border station at Panmunjom in the Demilitarized Zone in Paju, South Korea, on Tuesday, July 18. Not long after this photo was taken, Travis King, a U.S. soldier, bolted across the border and became the first known American detained in North Korea in nearly five years. (AP Photo/Sarah Jane Leslie)

State Department spokesperson Matthew Miller said Wednesday during a briefing that "The White House, the Pentagon, we here at the State Department, and the U.N. are all continuing to work together on this matter to ascertain information about the well-being and whereabouts of Private King.  

"We are still gathering facts, and I want to be very clear that the administration has and will continue to actively work to ensure his safety and return him home to his family," he added. 

MOM OF US SOLDIER WHO CROSSED INTO NORTH KOREA SAYS ‘I CAN’T SEE TRAVIS DOING ANYTHING LIKE THAT’: REPORT 

Map of where North Korea detained US soldier

A map shows the location of where a U.S. soldier crossed the Military Demarcation Line and was detained by North Korea, Tuesday, July 18, 2023. (Fox News)

Miller said "In terms of contacts with foreign governments, yesterday the Pentagon reached out to counterparts in the Korean People’s Army," but that his understanding is "those communications have not yet been answered." 

"We retain a number of channels though which we can send messages to the DPRK. As you can imagine, in a situation like this, those discussions are quite sensitive, and I’m not prepared to go into all the details at this time," Miller also said. "What I will say is that we here at the State Department have engaged with counterparts in South Korea and with Sweden on this issue, including here in Washington." 

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Demarcation Line Pyongyang

A United Nations Command soldier, right, and a South Korean soldier, left, stand guard before North Korea's Panmon Hall and the military demarcation line separating North and South Korea, at the Joint Security Area of the Demilitarized Zone in the truce village of Panmunjom on Oct. 4, 2022. (Anthony Wallace/AFP via Getty Images)

King, 23, joined the Army in January 2021 and is currently a cavalry scout with the 4th Infantry Division, a U.S. Army spokesperson previously has told Fox News. 

A U.S. Forces Korea spokesperson said King was on a joint security area orientation tour on Tuesday when he "willfully and without authorization crossed the Military Demarcation Line into the Democratic People’s Republic of Korea (DPRK)." 

Fox News’ Liz Friden contributed to this report.