Christine Lagarde, managing director of International Monetary Fund (IMF), recently spoke at an Atlantic Council meeting in Washington, D.C., about the sustainability of Greek debt.

Lagarde downplayed talk that differences in Greek data are the root of disagreements between the IMF and European creditors over Greek debt. The IMF has previously noted the debt as "explosively unsustainable."

During her talk, Lagarde defended the IMF's latest report on the debt and the Greek economy, noting that the IMF's role is to be a "ruthless truth-teller."