The United Nations, through its World Food Programme, plans to more than double the number of people it is feeding in Zimbabwe to 4.1 million by January 2020, it said on Tuesday.
Some 7.7 million Zimbabweans face severe hunger as the southern African country battles one of its worst food shortages in years.
An estimated US$293m is required for WFP's emergency response, with less than 30% of that sum secured.
In terms of logistics, WFP's planned expansion is a massive undertaking, not least due to limited availability of Zimbabwean dollars and skyrocketing prices for basics.
Food prices have remained elevated, with month-on-month food and non-alcoholic beverages inflation rates reaching 48.35% in October 2019.
The Zimbabwean government was recently forced to relax conditions of importation of grain in order to ensure the continued availability of essential foodstuffs, Fin24 reported.
Funds are required immediately if WFP is to meet the growing needs of the hardest-hit Zimbabweans, the world body said in a statement.
"We're deep into a vicious cycle of sky-rocketing malnutrition that's hitting women and children hardest and will be tough to break," said WFP Executive Director David Beasley.
"With poor rains forecast yet again in the run-up to the main harvest in April, the scale of hunger in the country is going to get worse before it gets better."
The crisis is exacerbated by a dire shortage of foreign currency, runaway inflation, mounting unemployment, fuel shortages, prolonged power outages and large-scale livestock losses, which have affected urban residents and rural villagers alike.