Action must be taken immediately to address the humanitarian crisis in the Sahel or other countries will be drawn in and it will "become a problem for the world", a UNHCR official warned Wednesday.

The volatile situation in Niger, Mali and Burkina Faso risks overflowing into neighbouring countries, the UN refugee agency's director for west and central Africa, Abdouraouf Gnon-Konde told AFP in an interview in Brussels.

"The Gulf of Guinea, Togo, Benin, Ghana, Cote d'Ivoire are already suffering because of the spiral of insecurity and the humanitarian situation -- the same with Mauritania, the same with Algeria," he said.

"If we don't act now, if we don't respond now, if we don't find a way to remain there, stay and continue to remain engaged, finding a solution, then somehow those countries will be overwhelmed, the state will be overwhelmed, and it will become a problem for the world," he said.

The official was on a visit to Brussels to stress to EU officials the need to stay focused on the African regions where some 10.5 million people have been displaced by conflict, even as the wars in Ukraine and Gaza dominate the news.

"Despite all the change, all the crises that we see in the world, despite all the conflict that we have, things are happening in the Sahel and that merits our attention," Gnon-Konde said.

The day before, he participated in an EU-hosted donors' conference for the Sahel. At the event, the European Commission pledged 201 million euros ($218 million) for vulnerable people in Burkina Faso, Cameroon, Chad, Mali, Mauritania, Niger and Nigeria.

Military regimes in Burkina Faso, Niger and Mali have pushed out troops from France, the former colonial ruler, and are increasingly turning to Russia for support as they battle jihadist insurgencies, causing wariness from Western donors.

Gnon-Konde said, for UNHCR, "it doesn't matter who is in charge" in those countries, as the most important thing was to respond to the needs of the civilian populations.

He added that Chad, located between Niger and Sudan, was emerging as "a testing case" for countries in the region, international donors and the UN.

Chad -- which has just announced its first government after three years of military rule -- is hosting nearly one million Sudanese refugees and "there is a risk that that number will increase by the end of the year," the UNHCR director said.