The European Union's executive says Europeans should not retire before 70 to save cash-strapped state pension funds.
In a paper to be published Wednesday, the European Commission says four workers' contributions to state pensions currently help support two retirees.
The growing number of older people would require the average retirement age to rise to 67 in 2040 and 70 by 2060 to maintain the current pension system, it says.
Lower birth rates and longer life expectancy mean that retiring earlier will not be sustainable.
Germany will raise the retirement age to 67 in 2029. Spain is considering a similar hike and Britain is discussing increasing it to 68.
But other countries are moving far more slowly. French President Nicolas Sarkozy is facing fierce opposition to his plans for people to retire at 62, instead of 60.
Pension reform is a key part of reducing future costs and tackling mounting government debt burdens.