Greek Prime Minister Alexis Tsipras and German Chancellor Angela Merkel spoke by telephone Monday and agreed that Athens would present proposals to a eurozone summit the next day, a Greek government source said.
"They agreed that the prime minister will present the proposals of the Greek government at the summit" on Tuesday, the source said.
The leftist government is scrambling to piece together a bailout deal before struggling Greek banks run out of cash, after the nation on Sunday rejected creditor demands for further austerity cuts in a referendum.
Tsipras on Monday also spoke to European Central Bank chief Mario Draghi and Russian President Vladimir Putin, while Greek President Prokopis Pavlopoulos rang French President Francois Hollande.
In the final tally early Monday, 61.31 percent of Greeks had rejected creditor demands for further austerity in return for more bailout funds, sending European stock markets tumbling.
The ECB is seen as the only institution capable of calming market panic and preventing the Greek economy from collapsing.