The risk of countries turning their back on global co-operation is the biggest challenge facing the world, as low growth and rising inequality fuel the rise of populism, said IMF managing director Christine Lagarde.

"It did not take the Brexit vote to understand that low growth, rising inequality, and a lack of jobs have combined with social and geopolitical concerns to fuel the rise of populism and inward-looking forces," Ms Lagarde said in the text of a speech on Thursday at the Centre for Global Development in Washington.

"The greatest challenge we face today is the risk of the world turning its back on global co-operation - the cooperation which has served us all well."

Britain's vote to leave the European Union last month has roiled global markets, raising the prospect that opposition to trade and immigration could stoke anti-EU sentiment across Europe and bolster US Republican presidential candidate Donald Trump.

Ms Lagarde said a breakdown in co-operation would hit low-income countries particularly hard.

Without a sharp increase in economic growth, one-third of the 60 low-income nations were unlikely to meet targets for reducing extreme poverty by 2030, she said.

Low-income countries face obstacles including climate change, violent conflict and the risk of failing to integrate a growing labour force. By 2035, the number of people reaching working age in sub-Saharan Africa would exceed that of the rest of the world combined, Ms Lagarde said.

"If we are not able to provide this coming generation with a livelihood and a chance to share in global welfare, we should be prepared for migration and political strife at an unprecedented level," she said.

"And let us have no illusions that this would stop at the water's edge, or at borders secured by a wall or chain-link fence."

Mr Trump has proposed building a wall at the US border with Mexico to prevent illegal immigration, a project he says the Mexican government should pay for.

Many poor countries need to broaden their tax bases, improve infrastructure and make growth more inclusive, Ms Lagarde said.

Bloomberg

What's she worried about? after Brexit, the Dow is now at an all time high of 8,516 and our All Ords, which hardly moved throughout, is at 5,537

You're right Boges, she's got her socialist panic mode hat on

Lagarde is like everyone else in the IMF. There fabulous personal wealth and power makes them believe that they are actually of some value to humanity.

A couple a years ago she was involved in a scandal where she got the IMF to pay billionaire Bernard Tapie $500million for doing . . . ABSOLUTELY NOTHING!

This coterie of global elite, who have the system so rigged they appoint each other to the top jobs in their various agencies, lie every day in the certainty that their words will be promulgated in the main news media as if they had been handed down from Olympus.

It is impossible to gain control over huge amounts of money, and not become influential in one's every move. Generally, these people avoid any publicity because their influence corrupts them. Lagarde has made the mistake of becoming visible. Her pay-off to Bernie Tapin is indecent. It shows her contempt for ordinary people.