Irish Prime Minister Enda Kenny said Monday that Greece can still return to negotiations with its international creditors to avert a default and possible exit from the euro.
In a letter to Greek Prime Minister Alexis Tsipras, Kenny said "for me, and I am sure for all our (European) colleagues, the door remains open to dialogue in a spirit of solidarity and responsibility".
Athens on Saturday called a surprise referendum for July 5 on the latest bailout proposal being offered to Greece, effectively breaking-off negotiations with creditors.
If no deal is reached, Greece looks likely to default on an IMF debt payment of about 1.5 billion euros ($1.7 billion) due on Tuesday, risking an exit from the eurozone and even the European Union.
Tsipras asked for Greece's bailout programme be extended for one month to allow the referendum to be carried out "in a calm and positive climate," but his request was swiftly rejected by eurozone leaders.
Athens now hopes to resume negotiations on Monday in line with the referendum result.
Kenny, who led Ireland through years of austerity after its own international bailout in 2010, said he had hoped for an agreement at the Eurogroup meeting on Saturday.
"We will continue to support the objective of a sustainable and mutually beneficial agreement, acceptable to all concerned, which will, as you say, return Greece to growth within the eurozone," he said.
He added: "Ireland itself experienced a very difficult economic period and worked its way through a programme of assistance and has great empathy for Greece and its people."
Earlier Monday, Ireland's deputy finance minister Simon Harris said he was "frustrated" by the hard-left Greek government's refusal to accept reforms because it was elected earlier this year on an anti-austerity ticket.
Urging Athens to "come back into the room", he said: "We need the Greeks to come back and do what Ireland did.
"Ireland wants Greece to remain in Europe, Ireland wants to help Greece find a solution but you can't have a solution when people are refusing to engage," he added.
Ireland's booming "Celtic Tiger" economy collapsed during the financial crisis and it, like Greece, was forced to accept a bailout from the European Union and International Monetary Fund.
But after deep spending cuts, tax rises, structural reforms and the sale of state assets, the eurozone country is now growing faster than any other EU economy.
But Irish socialist opposition party Sinn Fein has been more sympathetic to Athens, and a spokesman accused the European Central Bank, EU and IMF of "holding Greece to ransom".