North Korea has reopened a vital line of communication with South Korea, raising hopes of a diplomatic thaw days after Kim Jong-un said he would consider sending his country’s athletes to next month’s Winter Olympics, to be held just south of the border. Hours after Donald Trump again baited the North Korean leader on Twitter – this time with a boast about the size and efficacy of his nuclear button – Pyongyang said it would reactivate a telephone hotline at the truce village of Panmunjom at 6.30am GMT on Wednesday. According to the announcement, broadcast on state TV, the order to reopen formal communications along the border was given by Kim. “By upholding a decision by the leadership, we will make close contact with South Korea in a sincere and faithful manner,” said Ri Son-gwon, the head of the North Korean agency that handles inter-Korean affairs. He said Kim “highly appreciated and welcomed” the positive response by South Korea’s president, Moon Jae-in, to his New Year’s Day offer of talks on North Korean participation in the Olympics. “The leader stressed that whether inter-Korean ties can be improved totally depends on North and South Korea,” Ri said. The Pyeongchang Games open…