Oslo (AFP) - Donor countries on Friday pledged $672 million in emergency aid for people threatened by famine after eight years of Boko Haram violence in the Lake Chad region, but the sum is just a fraction of what the UN says is needed.
Fourteen countries meeting in Oslo agreed -- with the US conspicuously absent -- to contribute the $672 million (634 million euros) over three years, including $457 million for 2017 alone.
But the United Nations has estimated the Lake Chad region, which includes Nigeria, Niger, Cameroon and Chad, needs $1.5 billion this year.
UN aid chief Stephen O'Brien was nonetheless optimistic that target would eventually be met.
"In one morning we have raised a third of that," he said.
Boko Haram took up arms in 2009 in pursuit of an Islamic state in northern Nigeria.
Its insurgency has since spread to neighbouring states bordering Lake Chad, with frequent suicide bomb attacks.
Still, the hardest hit area has been northeast Nigeria, where at least seven soldiers were killed in a Boko Haram attack on military positions on Wednesday, according to a security source.
The conflict, which has left around 20,000 people dead and forced more than 2.6 million others to flee their homes, has aggravated an already difficult humanitarian situation in one of the poorest regions of the world.
People often have no access to schools, health care or agriculture, and it is difficult for humanitarian aid to get through.
"Nigeria and countries contiguous to the Lake Chad are experiencing one of the largest and gravest humanitarian crises in the world," Nigerian Foreign Minister Geoffrey Onyeama said.
"They can't farm the land, markets have stopped working, and food prices have skyrocketed," French Development Aid Minister Jean-Marie Le Guen noted.
"Faced with these enormous needs the international response is still insufficient," he added.
The $672 million pledged over three years is aimed at helping 10.7 million people in need.
Abdou Dieng, regional head of the World Food Programme, described the challenge of getting aid to the "most vulnerable of the vulnerable."
"Faced with a famine we're ready to do anything, including airdropping food. But it's a zone where we have to be very careful ... we don't want it to benefit the terrorists. This type of intervention is expensive," he said.
- US aid 'not factored in' -
The 14 donor countries who made firm commitments on Friday were almost exclusively western European nations, with the exception of Japan and South Korea.
But the United States, whose new administration has said it intends to slash its development aid budget, was not among them.
"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 told reporters.
Washington had sent a senior official from its aid organisation USAID to the conference, but he gave no clear indication of US President Donald Trump's intentions.
Other countries are also expected to commit aid soon, including Canada.