(NewsNation) — Democratic Rep. Brad Sherman of California said no significant concessions should be made to North Korea to bring back an American soldier who fled into the country, and is now in its custody.

Sherman, a long-time member of the House Foreign Affairs Committee, said the U.S. should not start empowering North Korea’s regime, or reliving sanctions on them, because one individual “decided to make a personal and stupid mistake.”

“We’ve got to look at the security of 300 million Americans, not just the one that we have a picture of,” Sherman said.

Two U.S. officials, according to the Associated Press, named the detained soldier as Pvt. Travis King. The soldier had recently been released from a prison in South Korea, where he’d been held on assault charges and was facing additional military disciplinary actions in America.

He had been escorted to the airport to be returned to Texas, but instead of getting on the plane, he left and joined a tour of the Korean border village of Panmunjom. That’s when he ran across the heavily armed border.

It is unclear how King managed to leave the airport while he was being escorted.

King, who is in his early 20s, is the first American detained in the country in nearly five years.

At a Pentagon news conference Tuesday, Defense Secretary Lloyd Austin said the department is closely monitoring the situation.

“This will develop in the next several days and hours, and we’ll keep you posted,” Austin told reporters.

Sherman called King’s decision to flee to North Korea “the biggest mistake” he’ll make in his life.

“The only fortunate part of it is it’ll hopefully direct our country’s attention to North Korean policy. We’re so preoccupied with Ukraine,” Sherman said. “The fact is that every day, North Korea’s creating more nuclear weapons and more technology to send missiles with those right to the United States or to our allies.”

The Associated Press contributed to this report.