The United Nations chief urged the government of oil-producing Angola to do more to reduce the large gap between the country’s wealthy and poor, a move he said would increase stability and unity in the sub-Saharan African nation.

Angola is Africa’s second-largest oil producer after Nigeria, but an estimated two-thirds of its population of 18 million people live on less than $2 per day."Angola has great wealth, but it also has large gaps between rich and poor,” U.N. Secretary General Ban Ki-moon said in comments published on the U.N. website late on Monday.Ban was speaking at the end of a 48-hour visit to Angola’s capital, Luanda, during which he met long-serving President Jose Eduardo dos Santos and other officials.