The prospect of a fourth summit between US President Donald Trump and North Korean leader Kim Jong-un is gaining traction ahead of the Apec summit in late October, observers say, amid signs that both sides may be testing the waters for a return to high-level nuclear diplomacy.Speculation intensified after North Korea’s vice-foreign minister, Kim Son‑gyong, travelled to New York last week – the first visit by a senior North Korean diplomat since 2019 – to lead Pyongyang’s delegation at the UN...