BERLIN: Greece's creditors say it must cut 14 billion euros ($17bn) from its budget in the next two years, 2.5bn euros more than they originally demanded, German weekly Der Spiegel reported.

The amount was revised upward as a result of the most recent audit mission by the country's so-called troika of bailout lenders, the European Union, the International Monetary Fund and the European Central Bank, Der Spiegel said.

Troika auditors visited Athens recently and are expected to return in September, when they have said they will remain for the entire month. Based on that audit, the EU and IMF will decide whether to release Greece's next loan disbursement of 31.5bn euros.

The Greek government is scrambling to slash its budget in order to access the funds, which it needs to keep it from defaulting on its debt and crashing out of the euro zone.

Der Spiegel said the troika had ordered the extra cuts because planned privatisations were not shaping up to be as lucrative as hoped and tax revenues were falling short of forecasts as the economy struggled through its fifth year of recession.

The auditors also said in a report that the government had so far been unable to show how it planned to reach the 11.5bn euros in savings it had already pledged to find for 2013 and 2014.