North Korea reopened a long-closed border hotline with South Korea on Wednesday, hours after U.S. President Donald Trump appeared to mock the North’s leader by saying he has a “bigger and more powerful” nuclear button than he does. The North’s decision to open the border phone line came a day after South Korea proposed high-level discussions amid a tense standoff over North Korea’s missile and nuclear programmes. That followed North Korean leader Kim Jong Un’s New Year address in which he said he was open to speaking with the South and would consider sending a delegation to the Winter Olympics to be held just across the border in Pyeongchang in February. U.S. officials said Washington would not take any talks between North and South Korea seriously if they did not contribute to denuclearising North Korea. A State Department spokeswoman said North Korea “might be trying to drive a wedge of some sort”. Kim ordered the reopening of the hotline at the truce village of Panmunjom at 0630 GMT on Wednesday, when South Korean officials at the border received a call from the North, the South’s unification ministry said in a text message. Officials on both sides were checking the line…