Josette Sheeran, a US undersecretary of state, appears almost certain to be named as head of the UN World Food Programme on Tuesday, in a decision diplomats fear marks an early blow to reform promises by Ban Ki-moon, the incoming secretary-general.

A UN official said that James Morris, the current head of the WFP, told senior staff at the weekend of the decision to appoint the US official candidate to a post traditionally viewed as a US fiefdom. The announcement, some diplomats believe, would be an indication that fledgling efforts to make appointments on technical merit have foundered.