US Secretary of State Mike Pompeo left Thailand yesterday after his hopes on resuming nuclear talks with North Korea were dashed. Pompeo left Bangkok after three days without progress on ending impasse in North negotiations as Pyongyang continued to launch ballistic missiles, heightening unease over prospects for a denuclearization deal.  Pompeo expressed disappointment that the North had sent neither its foreign minister nor a counterpart for the chief US negotiator to the Thai capital. <br />'' <br />'' Hopes of talk failed at a time when the trade war with China is escalating and relations between key American allies Japan and South Korea are breaking down. <br />''  <br />