A small delegation led by ex-New Mexico governor Bill Richardson and Google boss Eric Schmidt has urged North Korea to halt nuclear and missile tests.
Mr Richardson said the delegation had also called on authorities to widen Internet access and ensure "fair" treatment of a detained US citizen.
The group met officials in Pyongyang as part of a "private humanitarian mission".
The US government has described the visit as unhelpful.
Mr 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 last visit two years ago, he said Pyongyang had agreed to re-open its nuclear facilities to UN inspectors, but this did not transpire.
The delegation are due back in Bejing later in the day, where they are expected to address the media.
Message of openness
On Thursday, the former governor said his delegation's main message was that more openness would benefit North Korea.
"The citizens of [North Korea] will be better off with more cell phones and an active Internet," Mr Richardson told the Associated Press news agency.
"Those are the messages we've given to a variety of foreign policy officials, scientists and government officials."
One in 16 North Koreans now own a mobile phone, and the country is developing its own computer products, but it still has some of the world's tightest restrictions on communications with the outside world, the BBC's Lucy Williamson reports from the city of Seoul in South Korea.
Mr Schmidt has not commented on the reasons behind his visit, nor has Google.
Mr Richardson said the delegation had also asked officials to ensure "fair and humane" treatment of a US national currently detained in North Korea.
The prisoner 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.
The delegation's Pyongyang trip 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.
The US government has described the visit as "not particularly helpful".
"We continue to think the trip is ill-advised," US State Department spokeswoman Victoria Nuland said on Monday.