"We are confident that we will succeed, that the Greek debt is sustainable and therefore our programme will be successful," IMF European Director Antonio Borges told reporters on the sidelines of a conference. "We maintain our confidence in what is happening in Greece."

Borges urged patience as Greece implements an IMF-EU supported programme.

"These are not programmes that deliver miracles in a few months, therefore we are at the moment when economic consequences are more difficult to accept and people become more skeptical," Borges said, adding: "But this is a long-term programme, we will have to be a little patient."

Borges said Greece was not currently in the markets and could benefit from IMF and European assistance while being immune to market pressures.

"We just have to make sure the banking system remains strong and the Greeks have made quite a bit of progress on their banks," he added.