The United States appointed a new special envoy for Sudan on Monday, as Washington seeks to bring an end to a war that has wrecked parts of the country and killed tens of thousands. Former diplomat and US member of Congress Tom Perriello will assume the special envoy role, US Secretary of State Antony Blinken said in a statement provided to Reuters ahead of the announcement, as the US seeks to bring increased focus to the conflict after the failure of talks so far.