Greece will not present a list of economic reforms to euro zone finance ministers tomorrow, a senior EU official said, adding the country should be able to stay solvent until June.
Thomas Wieser, who heads the Eurogroup Working Group which prepares the decisions for the ministers' meetings, said Greece would in any case need to provide the list in the coming month.
"The clock is ticking. There won't be a new list in Riga, but over the course of May it must finally be reached," he told Austrian broadcaster ORF.
"The liquidity situation in Greece is already a little tight, but it should be sufficient into June."
Greece, which is running out of cash, told its euro zone partners in February that by the end of April it would agree with creditors on a comprehensive list of reforms to get the remaining €7.2bn.
Euro zone officials had expected the list to be presented tomorrow to the ministers meeting in Riga, but such hopes have dimmed.
The leftist-led government in Athens remains locked in a stand-off with its creditors - the euro zone and the International Monetary Fund - over the reforms.
Failure to unlock more funds would trigger a default, and possibly Greece's departure from the euro zone.
"It is my central belief that the negotiations with Greece can still be successfully finished," Mr Wieser added.
The reek deputy finance minister said yesterday that he hopes to get €2.5bn by forcing public entities to lend to the state, giving it enough room to meet its obligations through the end of May.
Shut out of bond markets, Athens is on the verge of bankruptcy and could run out of cash in weeks unless it strikes a deal with foreign creditors to unlock further bailout aid.
Prime Minister Alexis Tsipras's administration on Monday ordered state entities and local governments to park idle cash at the central bank for the state to borrow, triggering an outcry from mayors and regional officials who have threatened to challenge it in court.
"My target is €2.5bn," Deputy Finance Minister Dimitris Mardas told Greece's Star TV channel.
"I want this €2.5bn to cover any needs that may occur, I repeat, taking into account the worst case scenarios and the needs for May."
Mr Mardas initially said that the state was still short of €350-€400m to cover wage and pension payments at the end of April but later said that hurdle had been overcome.