Greece has moved a step closer towards a eurozone exit as early results from a crucial bailout referendum suggested Greeks had overwhelmingly rejected creditors' demands for more austerity.
Greece will have to introduce another currency if it votes 'No' in Sunday's referendum on its potential bailout terms, European Parliament president Martin Schulz said.
EU president Donald Tusk urged the bloc to avoid sending any "dramatic messages" even if the Greeks were to vote against bailout conditions in their weekend referendum.
Greece needs 50 billion euros over the next three years, including 36 billion euros more from EU lenders, to stabilize its finances even under existing creditor plans.
Greek Prime Minister Alexis Tsipras vowed to press ahead with a controversial bailout referendum as European leaders ruled out any fresh debt offer before Sunday's vote.
The International Monetary Fund said that allowing a borrower to delay repayment, as Greece has requested, is generally ineffective in helping a country overcome crisis.
Nobody in the halls of the International Monetary Fund in Washington has any illusion: Greece is going to default, delivering a new blow to the global crisis bank's credibility.
Irish Prime Minister Enda Kenny said that Greece can still return to negotiations with its international creditors to avert a default and possible exit from the euro.
Russian Foreign Minister Sergei Lavrov expressed the hope that Brussels would avoid "negative scenarios" over Greece amid fears that the country is heading for a eurozone exit.
It has already been dubbed "Black Monday" -- jittery housewives, shoppers and business owners queued in vain at cash machines in Athens, where the country awoke to capital controls and shuttered banks.
The president of the European Commission will make his latest proposals later to try to avoid a Greek default, adding that Athens was 'centimetres' away from a deal when discussions broke down.
The Greek government said it had called an emergency gathering of its systemic stability council, as speculation mounted of capital controls being imposed and increasing signs of a bank run.