The latest round of six-party talks over North Korea’s nuclear programme opened in Beijing on Wednesday with “very useful and business-like” discussions, according to the chief US negotiator, after North Korea shut down all its known nuclear facilities.

Christopher Hill told reporters the six sides, which include South Korea, Japan, Russia and China, discussed a timeframe for North Korea to declare, disable and verify all its nuclear-related programmes and material as well as how to deliver the 950,000 tonnes of fuel oil promised in return to Pyongyang.