French President Nicolas Sarkozy has said there are too many foreigners in France and the system for integrating them is "working badly".
In a TV debate, Sarkozy defended his plan to cut the number of new arrivals in half if he is re-elected next month.
Sarkozy is trailing in the opinion polls behind the Socialist candidate Francois Hollande.
He is also competing for conservative voters with the far-right National Front party led by Marine le Pen.
The president said while immigration could be a boon for France, it needed to be controlled more tightly through tougher qualification rules for residency.
Sarkozy, whose father was a Hungarian immigrant, also said he wanted to restrict some benefit payments to immigrants who had been in the country for 10 years.