Zambia must refine an initial debt-restructuring deal it announced with holders of $3 billion in eurobonds, the International Monetary Fund said.

“Further discussions and modifications are needed to bring this initial proposal more fully into line with the requirements of the program,” a spokesman for the Washington-based lender said Saturday in reply to emailed questions.

Zambia’s official bilateral creditors and the fund had expressed reservations about the in-principle agreement, the finance ministry said Friday, adding it was continuing discussions with a bondholders steering committee.

Read more: Zambia’s $3 Billion Bond Revamp Deal Raises IMF Reservations