Family members of US Army Pvt. Travis King said Wednesday night that they had no reason to believe the soldier, who last month crossed the border between North and South Korea in the demilitarized zone separating the two nations, would defect from the US military.

Jaqueda Gates, King's sister, told Laura Coates on "CNN Primetime" that the family has not received more information about her brother's whereabouts, but said that he is "not the type to just disappear."

"So, that's why I feel like the story is deeper than that," she said, adding: "I don't I don't believe that you just do vanished and ran away."

King -- who the US military said "willfully and without authorization" crossed into North Korea while taking a civilian tour of the Joint Security Area, a small collection of ​buildings inside the DMZ that has separated North and South Korea since the end of the Korean War in 1953 -- is believed to be the first US soldier to cross into North Korea since 1982.

As CNN previously reported, he had a history of assault, was facing disciplinary action over his conduct and was meant to go back to the US the day before the incident.

Myron Gates, King's uncle, told Coates that while the family has reached out to a variety of elected officials' offices, the family has not heard from the Biden administration and wishes the White House would do more.

"We wish they would come to our house to talk to us, and let us know something," he said.

The family, he said, has been contacted by family members of Otto Warmbier, who urged them to act. Warmbier, a US college student, had been detained in North Korea for 17 months after visiting in 2016 and died less than a week after returning to the United States in 2017.

Jaqueda Gates detailed the toll her brother's situation has taken on the family, saying it's been hard to sleep as they wait for updates and that King's absence has devastated their mother.

"This is really, really hard on my mom, you know, that's her baby boy," Gates said.

State Department spokesperson Matt Miller confirmed to CNN earlier Wednesday that the North Koreans had reached out to the United Nations Command in the last 48 hours about King, but said "it was not a substantive call" and there not seen "as progress in any way."

"The outreach that we have made to North Korea through diplomatic channels has still not been answered," Miller said at a State Department briefing.

The development comes after the deputy commander of UN Command said last week that a "conversation has commenced" with North Korea over King. Gen. Andrew Harrison said at the time that the case of King is still under investigation and he could not provide further detail on the private.

King's family vowed Wednesday night to push for his return.

"We're gonna continue to fight for you and we ain't gonna stop until you come home," Myron Gates said.