Germany's central bank is arguing that the country's retirement age should ultimately be lifted to 69 — a call that received a frosty response from the government.

The government decided a decade ago to raise the retirement age from 65 to 67. The increase is being introduced gradually and will apply to all retirees by 2029.

Since then, there have been periodic calls for people in Europe's biggest economy to work even longer. In its monthly report Monday, the Bundesbank said consideration should be given to raising the retirement age to around 69 by 2060 to stabilize the system as the population ages.

Chancellor Angela Merkel's spokesman, Steffen Seibert, said that the government "stands by retirement at 67."