Mr. Philippe said that “special” retirement schemes like those for railway workers had to disappear, and that the French would progressively have to work “a little longer.”

“These adaptations, these transformations, do we want to do them brutally, in a rush, or do we prefer to set them in place reasonably, progressively, without brutality, when we still have time?” Mr. Philippe said.

But he also tried to placate protesters, saying that his “logic” was not that of “confrontation.”

Mr. Philippe said that it would be “unreasonable, unacceptable, unfair, to change the rules mid-game” for employees who had made life and career choices based on their past pension rights and that he was “totally” ready to “ensure that transitions are progressive.” He also promised that teacher pensions would not go down.

Mr. Philippe is expected to lay out the specifics of the pension proposals in a speech on Wednesday, but it is unclear whether that will mollify the striking workers, some of whom have vowed to continue until the plans are scrapped altogether.

The lack of details so far has left many French residents, many of whom distrust Mr. Macron, believing that their pensions will decrease.