The World Bank has said that for the first time less than 10% of the world's population will be living in extreme poverty by the end of 2015.

The bank said it was using a new income figure of $1.90 per day to define extreme poverty, up from $1.25.

It forecasts the proportion of the world's population in this category to fall from 12.8% in 2012 to 9.6%.

However, it said the "growing concentration of global poverty in sub-Saharan Africa is of great concern".

Although the share of people in poverty in sub-Saharan Africa is projected to fall from 42.6% in 2012 to 35.2% by the end of 2015, this will still represent around half of the world's poor.

"We are the first generation in human history that can end extreme poverty," World Bank President Jim Yong Kim said.

The bank says the downward trend was due to strong growth rates in developing countries and investments in education, health, and social safety nets.

But Kim warned that continuing the progress would be "extraordinarily hard, especially in a period of slower global growth, volatile financial markets, conflicts, high youth unemployment, and the growing impact of climate change".

And the bank warned that poverty is "becoming deeper and more entrenched in countries that are either conflict ridden or overly dependent on commodity exports".