Oil-related corruption in South Sudan poses high laundering risk, US Treasury official says
Prior to its division, Sudan was considered one of the most corrupt countries in the world
West, Russia divided on U.N. council climate role
The UN Security Council "has an essential responsibility to address the clear-cut peace and security implications of a changing climate," US ambassador says
World not on track to eradicate polio - report
Report warns that although cases of polio have been cut by 99 percent since 1988, the disease will resurge if not stamped out