IMF Managing Director Christine Lagarde said Greece's national debt requires restructuring for bailout programs to work.
Speaking in Washington D.C., Lagarde said Greece needs to continue cost cutting reforms.
And she added: "The other leg is debt restructuring, which we believe is needed in the particular case of Greece for it to have debt sustainability. That analysis has not changed. It well may be that numbers may have to be revisited but our analysis has not changed."
The IMF and lead eurozone lender Germany are at odds over whether Athens should be offered debt relief — a request renewed Wednesday by Greece's government.
Athens is trying to negotiate a third bailout program — worth an expected 50 billion euros ($55 billion) — as it faces the risk of losing its euro membership.