Greece believes the demands of its international creditors are "irrational", a government source said Sunday after talks on its bailout ended without a deal.

"The demands of the creditors are irrational, the discussions lasted 45 minutes," the source said, pinning the blame on the IMF, whose position it said was "intransigeant and tough" because it was insisting on further cuts for pensions and a rise in value-added tax.