Rapid population growth in some of the Africa’s poorest countries could jeopardize progress towards reducing world poverty and improving health, according to a report by the charity foundation of the American businessman Bill Gates.

The demographic trends show that one billion people have escaped poverty in the past 20 years. The rapidly growing population, especially in parts of Africa, may, however, stop the decline in the number of extremely poor people in the world and it may even begin to increase.

“Population growth in Africa is a challenge”, said Bill Gates at a briefing.

According to the report, the poverty in Africa is increasingly concentrated in several countries that have one of the fastest growing populations in the world. It predicts that by 2050, over 40% of the world’s poorest people will live in two countries – the Democratic Republic of Congo and Nigeria.

Asked what are the best ways to tackle population growth and the challenge of poverty, Bill Gates said it was crucial to improve access to birth control, and this should be combined with investment in health and education for young people.

According to the UN figures, more than half of the world’s population growth is expected to be in Africa between 2015-2050. Its population is projected to double by 2050, and to increase by two more times by 2100.