Donor nations meeting in Oslo on Friday pledged $672 million (634 million euros) to the Lake Chad region, where the United Nations (UN) says some 11 million people -- roughly two-thirds of the population - are in need of urgent humanitarian aid.

The amount pledged was for three years, with $457 million dollars slated for 2017. The UN estimates $1.5 billion is needed this year alone to meet humanitarian needs in Nigeria, Niger, Cameroon and Chad, where seven million people are at risk of famine.

The four countries have been hit hard by a Boko Haram insurgency and military operations against the Islamist militant group.

UN Under-Secretary General Stephen O'Brien said "in one morning we have raised a third" of the appeal, adding he was optimistic the $1.5 billion target for the year would be met.

Fourteen countries pledged donations at the Norway hosted talks. Among the donors, Germany pledged $127 million, Norway $192 million, and the European Union another $111 million over three years.

"We must not look away, we must not turn a blind eye to the suffering in the Lake Chad region," German Foreign Minister Sigmar Gabriel said.

The United States, which under President Donald Trump has vowed to slash its foreign aid budget, did not contribute.

"The US said they would come back with their contribution, so it is not factored in" to Friday's sum, Norwegian Foreign Minister Borge Brende said at a press conference.

A seven year Boko Haram insurgency has killed more than 20,000 people and displaced 2.6 million from their homes. Nigeria's military says it has largely pushed back the militant group from the northeast of the country they once controlled.

But the conflict and continued attacks have disrupted economic activity, farming and trade in an already poverty-stricken region. Up to a million people remain out of reach of humanitarian agencies. A further three million people require immediate food assistance by July to avoid famine.

Adding pressure on local populations is a growing environmental disaster, with the water in Lake Chad disappearing and desertification hitting surrounding areas.

The humanitarian crisis in the Lake Chad region is not new, but has been one of the world's most overlooked crises.

For Europe, in addition to humanitarian issues, the crisis in the Lake Chad region has gained renewed urgency amid concern another migration wave could reach the continent's doorstep.

cw/jm (AFP, AP, dpa, Reuters)