ISLAMABAD, Pakistan (CNN) -- The mother of an American humanitarian worker kidnapped in Pakistan has pleaded for him to be freed in an audio recording released by the United Nations.
John Solecki is pictured with his parents Rose and Ralph during their visit to Quetta in April 2008.
Rose Solecki, whose son John was abducted three weeks ago, describes how the "happy memory" of visiting him in the province of Balochistan "turned into a nightmare."
"I simply do not understand why this is happening to our dear John," Rose Solecki, 83, says in the recording. "I cannot begin to explain the sorrows and pain I am going through right now. My husband and I are old. We want to be with John again. We cannot bear the thought of losing John."
John Solecki is the head of the U.N. High Commissioner for Refugees office in Quetta, a city in southwestern Pakistan that is the provincial capital of Balochistan. He was kidnapped February 2 on his way to work, the United Nations said. His driver, Syed Hashim of Quetta, was killed, police said.
It is not clear who abducted him.
"We don't know for sure exactly who these people are, because we haven't been able to make direct contact with them," U.N. spokeswoman Miki Shinohar said last week. "We're trying to really to work with different people, different communities, tribal leaders. We're trying different ways really to get more information about John's whereabouts."
A video that aired February 13 on Pakistan's Geo TV network appeared to show Solecki.
In the video, the man says, "This is a message to the United Nations. I am not feeling well. I'm in trouble. Please help solve the problem soon so I can gain my release."
Geo TV said the tape was sent to its News Online Web site and posted there before it aired on the network.
Solecki's mother says in the recording that she and her husband are archaeologists who worked in the region when John Solecki and his brother Bill were children.
"I myself lived and worked in Balochistan a long, long time ago as a young archaeologist. When John took up his assignment in Quetta, his father and I were delighted," she says. Read full transcript of mother's plea
"I was so proud of John and the work he was doing with such dedication. My husband and I spent a wonderful time meeting his friends in Balochistan," she continues in the recording, which lasts about three and a half minutes and was distributed to Pakistani media by the United Nations.
"To our friends in Balochistan, please help us find John and have him return safely to his family, friends and colleagues. John has helped many people in Balochistan, and now my son needs your help. Thank you," she concludes.
CNN's Zein Basravi contributed to this report.