Budget cuts to the United Nations’ refugee agency (UNHCR) are driving more migrants to Europe, said the organization’s chief Filippo Grandi.

“The budget cuts that are imposed on us by donors are catastrophic also from the point of view of how you manage these flows,” Grandi, the U.N. High Commissioner for Refugees, told the Financial Times in an interview published Monday.

He added that ignoring developments in African countries was “a big strategic mistake.”

“There is no doubt in my mind that people are already moving from Chad to Libya — Sudanese refugees,” Grandi said. “Give more assistance to states where people are ready to stay before going back home. You solve a lot of your problems by doing that.”

The UNHCR faces a massive budgetary shortfall after U.S. President Donald Trump pulled funding earlier this year from some U.N. agencies.

The U.S. was the UNHCR’s largest contributor, providing about 40 percent of its total donations, but other European countries like France, Germany and Italy have also cut support due to their own domestic belt-tightening.

The UNHCR has been forced to suspend about $1.4 billion in assistance programs since the U.S. and other countries cut support.