Greece wants a new economic deal with its EU creditors to enter into force from September 1, and says it must include social support measures and less harsh budget goals, a finance ministry source said Monday.

"It is in our interest to have the deal running from September 1," the source said, ahead of crucial talks with eurozone finance ministers on Wednesday.

The official added: "Our red line is the humanitarian crisis and a major reduction in the primary surplus targets."

Under the previous conservative government, Greece was to record a primary surplus -- the budget balance before interest payments on debt -- of around 4.0 percent of output in 2016.

The new leftist government is only prepared to deliver a surplus of 1.5 percent of output, the source said.

Athens is under pressure to woo its international creditors as quickly as possible because the European portion of Greece's EU-IMF bailout is due to expire at the end of the month.