In her media briefing, State Department spokesman Victoria Nuland said the two will be making the trip as private citizens.
"They are traveling in an unofficial capacity," Nuland said. "They are not going to be accompanied by any U.S. officials. They are not carrying any messages from us. Frankly, we don't think the timing of this is particularly helpful, but they are private citizens and they are making their own decisions."
North Korea has come under intense criticism from the United Nations and rest of the world for its long-range rocket firing last month which violated U.N. Security Council resolutions as it was seen as a test of its ballistic missile technology. The isolated Communist country is under tough sanctions for conducting two nuclear tests in 2006 and 2009.
Nuland said Schmidt and Richardson, former New Mexico governor, energy secretary and U.S. ambassador to the Untied Nations, are "well aware of our views" on North Korea.
The Wall Street Journal, quoting a source, has reported Schmidt intends to join Richardson and other members of a group planning the trip, likely to take place this month.
When asked if the trip might be tied to winning the release of a U.S. national being held in North Korea, Nuland said: "Again, they are not going on our behalf. No American official is going with them. They are not carrying any messages from us."
As regards the detained U.S. national, Nuland said the United States is "in contact with" North Korea through the Swedish Embassy. She said Swedish diplomats have been granted consular access to the U.S. national.
Nuland also reminded that U.S. companies are subject to restrictions stemming from U.S. economic sanctions against North Korea, while noting the United States supports the right of all people to have access to the Internet. Communist North Korea strictly limits Internet access by its people.