Greek Prime Minister Alexis Tsipras says he will call a referendum on the outcome of the negotiations with international creditors.
The bailout talks were taking place in Brussels overnight.
"The people must decide free of any blackmail ... the referendum will take place on July 5," Tsipras said on Greektelevision.
He addressed the nation before a critical meeting of eurozone finance ministers yesterday, amid heightened anxiety over a possible Greek default that could spark its exit from the eurozone.
"For the past six months, the Greek Government has led the fight ... to find a viable agreement that respects democracy," Tsipras said.
"We were asked to implement austerity measures allowing the deregulation of the labour market, pension cuts, and an increase in VAT on food products, targeting the humiliation of an entire people," he said.
"This is a historic responsibility that now appears for us to decide the future of the country ... in the coming days we will have to take decisions upon which future generations will depend."
Earlier Greece rejected its creditors' offer of a five-month, 12 billion ($19.6 billion) extension of its bailout programme.
The creditors — the European Commission, the European Central Bank and the International Monetary Fund — insist Greece must seal a deal this weekend to avoid an IMF default next week.
However, the Greek Government says the demanded reforms will be recessionary and the funding insufficient.
