North Korea asked America to arrange an Eric Clapton concert in Pyongyang, saying that it could help to persuade Kim Jong-il to allow humanitarian aid into the country.

A confidential cable dated 22 May 2007 from the US ambassador in Seoul to Washington reveals North Korean officials "suggested" to the Americans that because Kim Jong-il's second son, Kim Jong-chol, was "a great fan" of the British guitarist, a "performance could be an opportunity to build goodwill". The report adds that "arranging an Eric Clapton concert in Pyongyang… could be useful, given Kim Jong-il's second son's devotion to the rock legend".

The suggestion was unusual: rock and pop are forbidden in North Korea because of their western influences. But it appears to have met with some success: in 2008, it was reported that Clapton had "in principle" agreed to perform in North Korea in 2009.

The request was portrayed by North Korea as a way to "promote understanding" between the communist nation and the west. "These cultural exchanges are a way of promoting understanding between countries," a North Korean official said at the time, referring to plans by the New York Philharmonic Orchestra to perform in Pyongyang, while the North Korean State Symphony Orchestra would perform in London."We want our music to be understood by the western world, and we want our people to understand western music."

The plan later appeared to stall, however, with Clapton denying that he had agreed to take part. His spokeswoman put out a statement saying that he "receives numerous offers to play in countries around the world", and "there is no agreement whatsoever for him to play in North Korea".

Music has been used to advance the cause of diplomacy towards North Korea in the past, just as US orchestral visits to the Soviet Union were deployed in the 1950s during the cold war.

The New York Philharmonic visited Pyongyang in 2008 to play a concert that constituted the largest US presence in the reclusive state since the Korean war. The trip was authorised by the US state department amid deadlock on North Korea's nuclear programme.

At the time, it was welcomed by the then US secretary of state, Condoleezza Rice, although she cautioned against expectations that it would lead to dramatic change. "I don't think we should get carried away with what listening to Dvorak is going to do in North Korea," she said.

North Korean authorities went to unprecedented lengths to accommodate the orchestra, allowing a delegation of nearly 300 people to fly to Pyongyang for a 48-hour period and taking down the anti-American posters that usually line the streets of the city.

News of the Clapton request is revealed in a confidential cable detailing a briefing between the US ambassador in Seoul and a leading human rights worker in the region.

Despite increased openness by the North Korean ministry of public health to outside aid, the contact revealed the problems he faced as "an outsider [trying] to get anything done" in a country where "each institution seems to have veto power, but none has the power to push anything forward".

Describing his frustrations in trying to set up a health programme in North Korea, the contact said: "The only organisations that can really deliver are the military, which does not talk to anybody, or the Red Cross."

The contact also warned the US ambassador that North Korean families living abroad were being "milked for money before, during and after" reunions with relatives in the country.

"The DPRK's Overseas Compatriots Committee... extorts a tremendous amount of money from desperate families [who] must pay US$300 to apply and submit comprehensive personal and financial information," the cable reports.

"If selected, the families are forced to pay for unwanted sightseeing excursions in North Korea. Before they are finally able to see their relatives, which is always just hours before their departing flight, they are often told that the relatives had to travel to the meeting place by taxi and [owe] several thousand dollars in fare… These are desperate, old people who would pay anything."

After the trip, the cable continues, families abroad "typically get repeated correspondence from the North Korean government asking for money to assist the family members, who are sometimes falsely alleged to be ill". The contact urged the ambassador to set up a programme to help families wanting to reunite with North Korean relatives: "[He] said that North Korea would not run such an exploitative system if the United States government were involved."