"We are obviously aware of these reports that a US citizen has been detained in North Korea," State Department spokesperson Victoria Nuland told reporters.
"We obviously have no higher priority than the welfare of our citizens. As you may know, we have no representation in Pyongyang," she said.
The Embassy of Sweden acts as America's protecting power for issues involving US citizens in North Korea.
"I can't comment any further than that due to privacy considerations," Nuland said in response to a question.
South Korean media earlier reported that 44-year-old Kenneth Bae, a tour operator, was detained by North Korean authorities during a five-day visit to the country's coastal city of Rajin in early November, said Yonhap.
Bae was interrogated after authorities found a computer hard disk, according to Yonhap.