US, DPRK in regular contact via back channel
CGTN
["china"]
Regular contact has been taking place between US envoy Joseph Yun and the DPRK's UN diplomat Pak Song Il, AP has reported citing unnamed officials, adding that meetings are still ongoing.
It was known that the two sides were in contact attempting to secure the June release of American university student Otto Warmbier who was being held in Pyongyang for alleged anti-state activities. 
But it wasn’t known until now that contacts have continued, or that they matters other than US detainees have been discussed.
US Defense Secretary James Mattis has said America still hopes to solve the DPRK crisis using diplomacy.