Former Zambian agriculture minister, Guy Scott, told the BBC that the last year's drought was now over and after a good harvest there was now food available all over the country.
But World Food Programme spokeswoman Judith Lewis says there are still pockets where people needed food aid or could not afford to buy the food now on the market.
"We've got to be sure that we don't leave these people behind. And so that's what we're trying to look after - those pockets and those most vulnerable people who are still at risk in Zambia.
She says the needs are particularly acute among HIV-affected families and also in the southern district where there was not a good harvest.
But Mr Scott says that World Food Programme deliveries were delayed in arriving and what they are doing now is artificially cutting the food prices paid to commercial farmers.
"People are being targeted with food aid right in the middle of a bumper harvest," he said.
Genetically modified food aid was sent to Southern Africa during the drought, despite strong reservations expressed in Africa.
But Zambia banned the aid, saying it would rather go hungry than risk losing its export markets in Europe because its crops had been contaminated with GM seed.
The drought in Southern Africa is now over, but Zimbabwe's agricultural sector in particular remains in a poor state, after the government implemented a widely criticised fast track programme of transferring land ownership from white into black hands.
By sarah park