The International Monetary Fund said it stands is prepared to work with Greece and European Union partners to advance the third bailout effort for the country agreed early Monday.
Time was running out to get a desperately needed debt agreement in place after 10 hours of talks in Brussels, with Greece's economy and banking system at risk of imminent collapse.
Greek Prime Minister Alexis Tsipras told US Treasury Secretary Jacob Lew his country wanted the eurozone to provide a bailout, but one that "respects the Greek people".
German Chancellor Angela Merkel warned a Greek bailout deal would not come "at any price" as she arrived for a eurozone summit aimed at bridging gaps on how to keep Greece in the single currency.
International Monetary Fund Managing Director Christine Lagarde said that a new program to prop up Greece's finances would require creditors to restructure debt.
Greek banks will remain closed until Monday, the finance ministry said as the government raced to come up with a new proposal to present to creditors in a last-minute drive to avert a eurozone exit.
Greece's economic turbulence is dominating political debate in Spain ahead of a year-end general election, with the ruling conservatives pointing to Syriza's difficulties to discredit its Spanish ally Podemos.
German Chancellor Angela Merkel said that there was still no basis for talks on a new Greek bailout, as she arrived in Brussels for an emergency summit of eurozone leaders.
European Commission head Jean-Claude Juncker said he was against an exit by Greece from the euro, even though Greeks massively rejected bailout terms in a referendum this weekend.
International Monetary Fund chief Christine Lagarde said that the global crisis lender would assist Greece if asked, a day after Greek voters rejected a prior bailout plan.
Greek Foreign Minister Nikos Kotzias ruled out his country's exit from the EU and called for calm after Greek voters rejected bailout terms of international creditors.
German Chancellor Angela Merkel arrived for a meeting with French President Francois Hollande to take stock of Greece's resounding rejection of its international creditor's bailout proposals in a referendum.
The euro rose after Greece's Finance Minister Yanis Varoufakis announced his shock resignation, just hours after the cash-strapped nation rejected creditors' austerity demands in a landmark weekend referendum.