One of Kim Jong-eun's closest aides arrived in Beijing on Wednesday at a time when North Korea's nuclear activities and belligerent rhetoric have put China's relations with its traditional ally under increased foreign scrutiny.

Pyongyang state media said Choe Ryong-hae, vice-marshal of the Korean People's Army, had arrived in China as a "special envoy" of Mr Kim, North Korea's supreme leader. He later met Wang Jiarui, head of the international department of the Communist party of China’s central committee.

Mr Choe, a boyhood friend of the late leader Kim Jong-il, was appointed to his current position last year and is regularly seen close to Kim Jong-eun during his public appearances. His visit to China is the first by a senior North Korean official since last August, when Jang Song-taek – the country's de facto second-in-command, and Mr Kim’s uncle – met the Chinese president at the time, Hu Jintao.