South Africa has temporarily closed a key border crossing with Botswana due to heavy rainfall and flooding, the country's border authority said.

The Grobler's Bridge crossing in northern South Africa is used for trade, especially by miners in the Copperbelt region straddling Zambia and the Democratic Republic of Congo moving cargo to the port of Durban.

"Following consultations with our Botswana counterparts and thorough deliberation by the Port Management Committee, it has been decided that the temporary suspension of operations is necessary to prioritise safety," the Border Management Authority said in a statement.

The agency urged travellers and truck operators to use alternative routes.

The crossing links Botswana with South Africa's northern Limpopo province, which witnessed heavy rainfall last weekend.