The southern African country has struggled to feed itself since 2000, when President Robert Mugabe began a drive to seize white-owned farms to resettle landless blacks, leading to a sharp fall in agricultural output.

Production of the staple maize started to recover after Mugabe formed a unity government with his rival, Prime Minister Morgan Tsvangirai, and rose from less than 500,000 tonnes in 2007-8 to 1.45 million tonnes in the 2010/11 season.

Production is still below the 2 million tonnes a year the country needs to be self-sufficient.

The UN World Food Programme (WFP) said it was facing a $42 million funding shortfall for food aid it planned to provide to vulnerable households in Zimbabwe's hardest-hit areas until the start of the harvest season in March.

A recent study by the Zimbabwean government, UN agencies and other donor organisations had shown that 12 percent of the rural population would not be able to feed itself adequately through the lean season, the WFP said in a statement.