France, Dec. 29 -- The sum represents a fraction of previous US contributions but is presented as a generous commitment designed to preserve America's position as the world's largest humanitarian donor.

The money will be placed in a central fund and distributed to UN agencies under a new system of stricter oversight, a key condition of Washington's push for sweeping reform that has alarmed aid groups and forced deep cuts to services.

In recent years, total US humanitarian funding for UN-backed programmes has reached as much as €14.4 billion annually, according to UN data, of which €7- 9 billion came as voluntary contributions. Critics argue the drastic cut risks worsening hunger, displacement and disease and undermines US so...