The move is another sign isolated North Korea is gradually opening up following the resumption of train services between the capitals. BEIJING: Air China restarted direct flights between Beijing and Pyongyang on Monday (Mar 30) after a six-year hiatus, another sign isolated North Korea is gradually opening up following the resumption of train services between the capitals. China has acted as a lifeline for North Korea's moribund economy as its largest trading partner and an important source of