Paris: French President Nicolas Sarkozy on Sunday said that Europe's border-free Schengen agreement should be rethought and re-founded.

Sarkozy was addressing some 60,000 supporters in a reelection campaign in Villepinhte in the suburbs of Paris, ahead of the first round of the presidential vote April 22.

"The Schengen Agreement can no longer respond to the seriousness of the situation. They must be revised. There is a need to implement a structural reform that we have implemented for the euro," the conservative UMP candidate said.

"We cannot leave the management of migration flows only in the hands of the technocrats and the courts ... We need a government policy of Schengen as there is now a government of the euro area," the incumbent president added.

Sarkozy, who is currently lagging behind Socialist Francois Hollande in opinion polls, threatened to suspend France's participation in the Schengen agreement "if there was no serious progress in this direction within 12 months", as reported.

The Schengen Agreement signed June 14, 1985, near the town of Schengen in Luxembourg allows migrants to travel across Europe's border-free Schengen zone comprised of the territories of twenty-five European countries that approved the agreement.

In April 2011, when thousands of North African immigrants poured in Europe via Italy after unrests in Libya, Sarkozy and Italian authorities expressed willingness to adjust the Schengen agreement and better regulate illegal immigrants.