Under the new rule, for a four-year trial period, unspent funds are returned only to member states that have fully paid their mandatory contributions to the UN. Previously, unspent funds were returned to members even when those funds had never been deposited in the first place.

In a statement released the same day, UN Secretary-General António Guterres said he welcomes the decision, adding that the reform "will allow us to manage resources, especially for regular and peacekeeping budgets, in a more predictable and responsible way, and to better deliver on the mandates given by member states." The move is critical for the UN's immediate operational continuity, he said, adding that he had repeatedly called for this change since the beginning of his tenure.

According to the UN chief, the new regulation will "greatly benefit my successor who will no longer be hamstrung by being forced to return funds that were, all too often, never even received in the first place."