French Foreign Minister Bernard Kouchner suggested Tuesday reinforcing sanctions against Iran after its president announced increased uranium enrichment activities. Kouchner said Iran's announcement Tuesday that it had begun installing 6,000 new centrifuges at its uranium enrichment plant in Natanz was "dangerous." "If that continues, we must reinforce sanctions, but we also must continue dialogue," Kouchner told a news conference in Paris. "I fear that we will have to continue on the road toward sanctions if we don't get any response from the Iranians," he said. He did not elaborate on how existing sanctions could be strengthened. The United Nations has already imposed three sets of sanctions against Iran over activities that Tehran says are aimed at producing nuclear energy but which some world powers fear could be used to build nuclear weapons.