(CNN) -- The wife and son of an 85-year-old American being held in North Korea called for his release Monday, saying they need him back at the head of the table for Thanksgiving.
Merrill Newman of Palo Alto, California, was pulled off a plane in Pyongyang. He has been detained ever since.
His wife, Lee, said she would like to remind authorities in North Korea that Newman has been held for 30 days.
"We need to have Merrill back at the head of the table for the holidays. And we ask -- respectfully -- for them to release him and let him come home," she told CNN's Wolf Blitzer.
Asked what she would like to tell her husband, Lee Newman said simply: "We're missing you, and we want you home."
Washington does not have diplomatic relations with Pyongyang, and it has been working through Sweden -- the U.S. protecting power in North Korea -- to obtain information about the American.
"We've had talks with the State Department, regular conversations since the detention. I think they've been working very hard to secure the release, to establish sufficient communications to get some feedback. But at this point, we don't think there's been any official feedback," said Newman's son, Jeff.
"The Swedish consulate, which would be the first touch point, hasn't had any contact with him and that's what we need to know -- if nothing else to just establish his well-being and the fact that he's getting his medication."
The family has said Newman suffers from a heart condition and only had enough medication for the trip. They have sent packages of medication but do not know whether he has received them.
Newman, a Korean War veteran and retired financial consultant, was last seen aboard a flight from Pyongyang to Beijing. Just minutes before the plane was to depart, he was removed from the flight by North Korean authorities.
According to his family, he had been on a 10-day organized private tour of North Korea. From phone calls and postcards he sent, the trip was going well and there was no indication of any kind of problem, his son said.
"We just want nothing more than to have this misunderstanding put behind us," Jeff Newman told Blitzer.
"The right thing to do would be to put him on a plane and let him come back and join his family that loves him and misses him in California."
Newman is one of two American citizens being held in North Korea.
The other one, Kenneth Bae, was arrested in November 2012 and sentenced in May to 15 years of hard labor. The North Korean government has said he was found guilty of "hostile acts" and attempts to topple the government.
North Korea has not publicly said why it is holding Newman.
Among the possibilities is his military service. He served as an Army infantry officer during the Korean War, which saw North Korea fight South Korea, the United States and the United Nations between 1950 and 1953.
An armistice signed in 1953 ended the three-year war between North Korea and South Korea. The two sides technically remain at war.
"His time that he spent in the service was an important part of his life as a young man, and he was, I think, trying to put closure on that," said Newman's wife.
"He always has had an interest in the world, a respect for the Korean people, and he was looking forward to this as an opportunity to see the country -- for whatever opportunity he might have to see the people -- and to come back with a sense of comfort on having completed that circle."
It is also possible North Korean authorities mistook him for another Merrill Newman, a Korean War veteran awarded the Silver Star for valor in combat.
North Korean authorities are known to routinely run background checks on foreigners, travel agencies warn potential visitors.
News of the detention came as talks were under way between the United States and China, North Korea's closest ally, about reviving negotiations to dismantle Pyongyang's nuclear program.
The timing raises questions about whether North Korea plans to use Newman as a bargaining chip in the negotiations, a move the West has previously accused it of using to try to gain concessions from negotiations.