The sister of Kim Jong-un has insisted that North Korea will never give upits nuclear weapons, setting back hopes of progress towardsdenuclearisation during Monday’s visit to Pyongyang by President Xi ofChina. Kim Yo-jong, a senior figure in the leadership who sometimes servesas spokeswoman for her brother, said North Korea’s “status as a nuclearweapons state is the line of no retreat and it is a stark reality whetheranyone recognises it or not”…