The Republic of Congo has signed an agreement to lease 200,000 hectares of land to South African farmers.
Congo's agriculture minister said it would bring expertise to the country and reduce its dependence on imports.
South African farmers' union Agri SA, which signed the deal, said the ANC government's land policy was forcing white farmers to seek land abroad.
The ANC is seeking to transfer some farms, overwhelmingly white-owned, to the black majority population.
Under the terms of the agreement, South African farmers will lease the land in Congo for 30 years to produce food and fibre mainly for the domestic market.
Congolese officials say the land is made up of abandoned farms that the state used to operate.
"We import lots and it's not normal that with the resources at our disposal we remain food insecure," said Congo's Agricultural Minister Rigobert Mabundu.
"That's why we are doing programmes to mobilise Congolese to work in agriculture and... to complete this effort we need international co-operation - it's that which justifies the agreement."
Agri SA says so far nearly 2,000 farmers have expressed interest in going to Congo - most as an expansion of their South African operations.
The BBC's Jonah Fisher in Johannesburg says leasing land to foreigners to farm is a growing phenomenon across Africa.
But this is thought to be one of the biggest deals involving Africans investing in each other's countries, he says.