The International Monetary Fund (IMF) analysis on Greece released on Thursday will need substantial debt relief and 50 billion euros in new financing until 2018 in order for its debt to be sustainable. The IMF report revised its earlier forecast for Greek debt, predicting that this will start at 150% of the GDP in 2020 and closer to 140% of the GDP in 2022.

“Using the thresholds agreed in November 2012, a haircut that yields a reduction in debt of over 30 percent of GDP would be required to meet the November 2012 debt targets,” said the fund’s report. It also underlined that the new financial assistance program proposed by the institutions to Greek authorities will require 36 billion euros in “new European money” over the three-year period.

It said further concessions will be necessary to restore debt sustainability noting the “fragile” dynamic of the country’s public debt whereas it called for broader consensus among the country’s creditors.

The IMF says creditors must offer Greece discounted interest rates and a longer repayment period. It proposed extending a period of grace for the memorandum loans to 20 years and the gradual repayment of loans given by the EU over 40 years.