German Chancellor Angela Merkel, French President Francois Hollande and Greek Prime Minister Alexis Tsipras spoke by phone Saturday to discuss Greece's debt crisis as time runs out to reach a deal, a French diplomatic source said.

"They took stock of the situation to help move forward the negotiations between Greece and the three (creditor) institutions," the source said. The three-way talks came on the eve of a G7 summit in Germany that looks set to be overshadowed by the Greek drama.