The World Food Programme (WFP) fed 2 million people in October, the first month of a large-scale aid project. That will double this month and rise to 5.1 million — almost half the population — by early 2009.
"There is currently no food in the pipeline for distributions in January and February — just when the crisis is reaching its peak," the agency said in a statement in which it called for $140 million in additional funds to secure its Zimbabwe operations until the end of March.
Zimbabwe has been grappling with food shortages since 2001.
Opponents of President Robert Mugabe say his policy of forcing white farmers off their land has exacerbated the problem in a country where hyper-inflation has crippled the economy.