China’s special envoy for North Korea said on Friday there were “complex” reasons why he has yet to visit the country, but that China’s efforts to help bring about the denuclearisation of the Korean peninsula and foster peace were relentless and unchanged. Vice foreign minister Kong Xuanyou, who is ethnically Korean, became Beijing’s special envoy to North Korea in August. His predecessor, Wu Dawei, made his last publicly announced visit to North Korea in early 2016, urging restraint after Pyongyang announced a plan to put a satellite into orbit with a long-range rocket. “The reason I’ve not been to North Korea since being appointed the Chinese government’s special envoy for Korean peninsula matters is very complex,” Kong said. US and allies want harder line on North Korea sanctions but will China and Russia agree to tougher measures? “But no matter whether or not [I] go to North Korea, our firm stance on being dedicated to maintaining peace and stability on the peninsula and the denuclearisation process has not changed. “Our proactive diplomatic mediation work has also not stopped for a moment.” Song Tao, who heads the ruling Communist Party’s international department, was the last top official from China to go to North Korea, in November. Song was there to discuss the outcome of a party congress in China and statements from both countries made no mention of the nuclear crisis. North Korea has shown less and less interest in dealing with China diplomatically over its weapons programme or listening to Beijing’s pleas. North Korean hockey players cross the border to join up with Southern compatriots for Winter Olympics China is North Korea’s closest ally, but it has been infuriated by the North’s repeated missile and nuclear tests and has signed up for increasingly tough UN sanctions on the isolated nation. Kong said China welcomed a recent improvement in the situation, with the two Koreas reaching agreement on North Korea’s participation in next month’s Winter Olympics. China says sanctions are not the final way to resolve the issue, and has repeatedly called for a return to diplomacy and the restart of a six-party talks process with North Korea. The talks include China, the two Koreas, the United States, Russia and Japan, and collapsed in 2008.