Greek conservative leader Antonis Samaras underwent surgery for a detached retina Saturday. The doctor treating him has forbidden him from flying. (Petros Giannakouris/Associated Press)

Greece's new prime minister will not be well enough to travel to a critical EU summit in Brussels after undergoing an eye operation, the government said Sunday.

Antonis Samaras, 61, underwent surgery for a detached retina for nearly four hours Saturday, just three days after being sworn in at the head of a three-party coalition government formed after two inconclusive general elections.

The doctor treating the prime minister, Panagiotis Theodosiadis, has ruled out him being able to travel to Brussels for the June 28-29 European Union summit, government spokesman Simos Kedikoglou said.

"Before the surgery, [Samaras] said, `You do your job, and I do mine, which is to go to the EU summit,"' Theodosiadis said of Samaras. `I was hoping [Saturday] that he would announce he would not go because it was a very delicate operation. ... He needs to lie at a certain angle for a certain period each day, for at least a week. He can do meetings, but he certainly can't walk," Theodosiadis said, adding that his patient would leave the hospital Monday.

Samaras has appointed new Foreign Minister Dimitris Avramopoulos to head the Greek delegation at the meeting, Kedikoglou said.

The summit could prove a key test of Greek leaders' pledges to renegotiate some terms of the country's international bailout.

Reports that the so-called troika of Greece's lenders -- the European Commission, the European Central Bank and the International Monetary Fund -- will postpone the visit of its delegation, originally planned for Monday, were not confirmed by Samaras' office. European Commission spokesman Amadeu Altafaj Tardio said that troika staff "will be moving to Athens starting [Monday]."

The debt inspectors are due to review the country's fiscal situation and resume talks that had been put on hold during the country's nearly two-month political deadlock.

Finance minister suffers collapse

Greece's incoming finance minister, Vassilis Rapanos, was also hospitalized Friday after suffering a collapse. A hospital spokeswoman said he was expected to be discharged either late Monday or Tuesday after further tests. But because his swearing in had to be postponed due to his ill-health, outgoing Finance Minister Giorgos Zanias still holds the title and will attend the summit.

Zanias, who was a key negotiator for Greece's bailout deal before being named to the post, will be accompanied by Development Minister Costis Hatzidakis and Alternative Finance Minister Christos Staikouras.

Zanias himself had suffered chest pains and high blood pressure and was hospitalized in October at an EU summit, where he had accompanied then-Finance Minister Evangelos Venizelos. The doctors had said he had suffered an anxiety attack. Four days later, an adviser to then-Prime Minister George Papandreou suffered a heart attack during negotiations on Greece's second bailout deal.

Greece has been dependent since May 2010 on funds from two international rescue loan deals with other European Union countries and the International Monetary Fund, in return for which it imposed a series of deep spending cuts and tax hikes.

Anti-bailout parties made massive gains in Greece's May 6 and June 17 elections, with Greeks furious at the drop in living standards by measures that have left the country struggling through a fifth year of recession and sent unemployment spiraling to above 22 percent.

Samaras' conservative New Democracy party came first in both elections, but without enough votes to govern alone. Coalition talks collapsed after 10 days in May, leading to the second ballot.

New Democracy is now in a power-sharing government with longtime socialist PASOK rivals and the small Democratic Left.

The new government on Saturday issued a policy statement outlining what it aims to change in its bailout conditions, saying it would seek to repeal some taxes, halt layoffs and extend by two years the mid-2014 deadline for tough austerity measures.

"The general aim is no more cuts to salaries and pensions, no more taxes," the statement said, adding the government would not carry out any public sector layoffs.

Whether the government can deliver on its pledges will depend on how they are viewed by Greece's international creditors. Germany, the largest single contributor to the bailout, has repeatedly said Athens must stick to its austerity targets.

German Finance Minister Wolfgang Schaeuble repeated this view Sunday, in an interview to newspaper Bild am Sonntag.

"It must now be the most important task of Prime Minister Samaras' new government to swiftly and immediately implement the agreed program without hesitation or asking, yet again, what the others could do in addition for Greece," German Finance Minister Wolfgang Schaeuble was quoted as saying.

"The ball is in Greece's field; it is in their hands to achieve that Europe's citizens can regain trust. But this will only be achieved through concrete measures and actions."