A US envoy said Monday that Sudan peace talks in Switzerland were looking for ways to open three humanitarian routes to get desperately needed food into the war-torn African state. The key Adre crossing from Chad could open as soon as Tuesday and 100 trucks were waiting at the border, Tom Perriello, US special envoy for Sudan, told a media briefing. “Our first priority is to look at how to open three roads that collectively would ensure that 20 million people who are currently cut off completely or largely from food and medicine would be able to get that relief,” the envoy said. Perriello list…