Richardson has been to North Korea a number of times in the past two decades and has been involved in negotiating the release of US citizens held in the isolated country.
He told CNN Friday that he expected to meet with several senior officials in North Korea, though talks with North Korean leader Kim Jong-Un were “very doubtful”.
He added that he hoped the trip would be “positive” and dismissed US concerns, saying it had already been postponed once at Washington's request and that the State Department should not be “nervous”.
Both he and Schmidt would be travelling as private citizens, representing neither the US government nor Google, he said.
Also on the trip were Richardson's longtime aide on North Korea, K.A. “Tony” Namkung, Jared Cohen, director of Google Ideas, a think-tank run by the California-based Internet giant, and some staff, according to a statement from Richardson's office.
Bae, who was arrested in November, entered the country as a tourist, according to North Korea's official Korean Central News Agency. The agency said he had admitted committing a crime against the state.
Nolan Barkhouse, spokesman for the US embassy in Beijing, said Sunday that Richardson's trip was unrelated to the authorities in Washington.
“They will not be carrying any messages from the US government,” Barkhouse told AFP, adding: “They will not be accompanied by any US officials.”Richardson last visited the North in 2010 when he met its chief nuclear negotiator in a bid to ease tensions after the country shelled a South Korean border island.
North Korea last month angered the US and others by launching a long-range rocket it said was a satellite, but that Washington, South Korea and Japan said was a ballistic missile test.