Greece's new Prime Minister Antonis Samaras will miss this week's EU summit while he recovers from eye surgery, according to a government spokesman.
He underwent routine surgery on Saturday for a damaged retina, with the operation said to have been a success.
Mr Samaras was sworn in as prime minister only last Wednesday to head a three-party pro-austerity coalition.
The "troika" of rescue lenders have also postponed a planned visit to Athens due to Mr Samaras' poor health.
Inspectors from the EU, European Central Bank and IMF had been due to review Greece's progress in meeting bailout conditions on Monday.
The new date for the trip will be determined later in the week.
Greece is under huge international pressure to fulfil bailout terms.
The new governing coalition consists of two "pro-memorandum" parties who broadly support continuing the austerity and reforms demanded by Greece's lenders - Mr Samaras' centre-right New Democracy and the beleaguered socialist Pasok party - as well as the more sceptical Democratic Left.
The new government is seeking to water down the requirements imposed on it by other EU countries and by the International Monetary Fund, including an extension to the deadline for it to reduce its budget deficit by at least two years, to 2016.
The Greek reform programme was expected to be a major item on the agenda of the two-day EU summit in Brussels that begins this Thursday.
A government spokesman said that Mr Samaras cannot attend because doctors have forbidden him from flying, and that the new foreign minister, Dimitris Avramopoulos, will go in his place.
To compound the government's difficulties, the new finance minister Vassilis Rapanos is in hospital after apparently fainting on Friday.
His condition was said on Saturday to be "stable and improving". He was originally due to be sworn in on Saturday.
The outgoing finance minister, Giorgos Zanias, will instead travel to the summit along with two deputy ministers.
Both politicians are expected to be discharged on Monday, but Mr Samaras is likely to be confined to his home for a week.
In a policy document, the government said its aim was for the fiscal target envisaged by the bailout deal to be met without further cuts to salaries and pensions.
Elections held last week ended a two-month deadlock over its implementation.
Pro-bailout parties gained a narrow majority in parliament, despite widespread public anger at austerity measures stipulated in the bailout.
The government's negotiation document was published following agreement on policy goals between the coalition partners New Democracy, Pasok and Democraftic Left, and precedes a confidence vote in parliament.
It includes provision for "an extension to the period for the fiscal adjustment by at least two years, so that the fiscal target is met without further cuts in salaries and pensions".
"The aim is to avoid layoffs of permanent staff, but to economise a serious amount through non-salary operational costs and less bureaucracy," it said, quoted by AFP.
Under the current bailout deal, Greece has agreed to take 150,000 civil servants off the payroll by 2015.
Other provisions include:
- reviewing minimum wage cuts and measures to facilitate private-sector layoffs
- employers and unions to be allowed to set a private sector minimum wage
- rearranging taxpayers' arrears for the year so that they do not exceed 25% of income
- reducing VAT in catering from 23% to 13%
- extending unemployment benefits
Greece's new cabinet was announced two days ago.
All three parties have signed a agreement to fully support the coalition, giving it a majority of 29 in parliament.
However, the cabinet is dominated by the conservative New Democracy party, after its left-wing partners Pasok and Democratic Left barred their MPs from joining.
They are represented by two party officials each. It is believed that they may not want to be associated with austerity measures.
The BBC's Mark Lowen in Athens says the test for the new government will be to win significant concessions from eurozone partners in the weeks ahead.
Eurozone officials say the bailout should only be revised to reflect the deeper recession, and delays to implementation caused by inconclusive elections in April and the subsequent failure to form a government.
The country got an initial EU-IMF package worth 110bn euros (£89bn; $138bn) in 2010, then a follow-up this year worth 130bn euros.
It has also had 107bn euros of debt, held by private investors, written off.