Ten ministers were due to take part in the meeting, including Finance Minister Evangelos Venizelos who attended an informal gathering of Eurozone finance ministers in Poland Friday and Saturday.
That meeting in the Polish city of Wroclaw highlighted differences over cash aid for Greece and other indebted member states.
At a July summit in Brussels, the eurozone decided in principle on a second bailout for Greece of around 159 billion euros ($219 billion) but the details have not been worked out.
The Wroclaw meeting decided to delay until October a decision on eight billion euros of bailout loans blocked until Greece has convinced auditors it is on track to cut its deficit.
Venizelos stressed that "the situation was serious" and explained that the decision taken Saturday to cancel the ptime minister's trip to New York "was not due to an economic threat but to the need to take initiatives to help the country deal with this pressure," according to an official statement.
"We have no room for (budgetary) manoeuvre," government spokesman Ilias Mossialos said in an interview with the daily Kathimerini published Sunday.
He called for a "national consensus" and respect for a new real estate tax which caused a firestorm but is, in his words, "necessary to save the country from collapse".