Zambia's Afreximbank loan is commercial and will be restructured, the country's treasury secretary said on Friday.

"We are still negotiating with them. The debt will be restructured," Secretary to the Treasury Felix Nkulukusa told Reuters in Lusaka in response to a question on the status of Zambia's loan with Afreximbank.

"It's not a concessional loan, it's a commercial loan."

The African development lender has argued that as a multilateral institution like the International Monetary Fund or World Bank, which lends on concessional terms, below market rates, it is exempt from taking losses when countries default.

However, some of Afreximbank's lending is at commercial rates, which is generally in scope for restructuring.

Sources told Reuters in April that the Paris Club group of official lenders has made it clear that Zambia must restructure their debts to Afreximbank.

Zambia owes Afreximbank $45-million, according to think tank ODI.

Fitch downgraded Afreximbank's credit rating to one notch above junk earlier this week, with a negative outlook, citing high credit risks and weak risk-management policies.