PARIS — French President Nicolas Sarkozy vowed Wednesday to press ahead with his contested overhaul of the country's pension system and unions promptly announced new national strikes and protests, a day after bringing more than 1 million people to the streets.

The conservative leader said he is "attentive to the worries that were expressed" by protesters, who protested in 220 French cities Tuesday. But Sarkozy reiterated it was "out of the question" to give up on the plan to raise the retirement age from 60 to 62 under the reform.

With baby boomers reaching retirement age and life expectancy on the rise, the government insists the raised retirement age is necessary, so the money-draining pension system can break even by 2018. The reform is seen as a cornerstone of Sarkozy's political agenda and a key test for the conservative French leader ahead of 2012 presidential elections.

Unions said it's a threat to hard-won social benefits and want the reform drastically scaled back. Mobilized by Tuesday's protests, six leading unions met Wednesday and announced new nationwide strikes and demonstrations for Sept. 23.

Speaking Wednesday during a Cabinet meeting, Sarkozy conceded the government's willingness to negotiate on smaller details of the reform, including measures for the disabled and people in physically difficult professions. Sarkozy's office reported his remarks in a statement.

The reform is "a lasting and just response that will allow us to save our pension system," government spokesman Luc Chatel told reporters following the Cabinet meeting.

Chatel added that Labor Minister Eric Woerth has been charged with amending the bill to reflect the small changes, which is to be voted on by the National Assembly, the lower house of parliament, next week.

Labor leaders have called Tuesday's strike a major success. The strike forced the closure of schools and snarled traffic throughout the country Tuesday, as more than 1.1 million people demonstrated throughout France, according to the Interior Ministry. The CFDT union put the number of protesters at 2.5 million.