Eric Schmidt and Bill Richardson in North Korea visit

Google chairman Eric Schmidt and former New Mexico governor Bill Richardson are in North Korea on a visit described as unhelpful by the US government.

Speaking in Beijing before flying to Pyongyang, Bill Richardson said the visit was “a private humanitarian mission”.

He said he planned to raise the case of a US citizen detained in North Korea.

Bill Richardson has visited North Korea several times in the past, most recently in December 2010.

On two occasions he helped secure the release of detained US nationals. After his most recent visit he said Pyongyang had agreed to re-open its nuclear facilities to UN inspectors, but this did not transpire.

The detained US national is Korean-American Kenneth Bae, who was arrested in November in circumstances that are not clear. North Korea has in the past released detained Americans after high-profile US visits.

Google, meanwhile, has not commented on Eric Schmidt’s trip.

“This is not a Google trip, but I’m sure he’s interested in some of the economic issues there, the social media aspect. So this is why we are teamed up on this,” Bill Richardson said.

“We’ll meet with North Korean political leaders. We’ll meet with North Korean economic leaders, military. We’ll visit some universities. We don’t control the visit. They will let us know what the schedule is when we get there,” he said.

Internet use is highly restricted in North Korea, where few people have access to a computer and most users can only access a national intranet rather than the world wide web.

The visit comes less than a month after North Korea put a satellite into orbit using a three-stage rocket – a move condemned by the US as a banned test of long-range missile technology.

“We don’t think the timing of this is particularly helpful,” State Department spokeswoman Victoria Nuland said late last week.

Bill Richardson said the delegation was expecting to be in Pyongyang for two and a half days.