North Korea confirmed to Swedish diplomats that it is holding 85-year-old Merrill Newman of Palo Alto, California, and that he has been detained in the country since October 26, CNN reported. They did say why.

The U.S. State Department, who does not have diplomatic relations with North Korea, said it has been working through Sweden, the U.S. protecting power in the Asian country, to obtain information about Newman, news reports said.

"We are working in close coordination with representatives of the Embassy of Sweden to resolve this issue, and they also have requested on a daily basis consular access," Jennifer Psaki, the State Department spokeswoman told reporters on Friday.

This comes on the same day the 85-year-old's wife had pleaded for his release, news reports said.

"The family feels there has been some dreadful misunderstanding leading to his detention and asks that (North Korea) work to settle this issue quickly and to return this 85-year-old grandfather to his anxious, concerned family," Lee Newman said in a statement.

"We have had no word on the state of his health, whether or not the medications sent to him through the Swedish Embassy in North Korea have been delivered or why he was detained," the statement added.

Newman is a Korean War veteran, and been seen aboard a flight from Pyongyang to Beijing, China. "Just minutes before the plane was to depart, he was removed from the flight by North Korean authorities, the family has said," CNN reported.

"We've heard anything. We've worked through the State Department from the day he was supposed to depart... but we've heard nothing," said Jeffrey Newman, Merrill's son.

Secretary of State John Kerry called on North Korea to release Newman.

Kerry said that Newman's detention was one of many "disturbing choices by the North Koreans," in a MSNBC interview.