Paris ? The United States and five other world powers gave Iran a stern ultimatum Wednesday, announcing they would seek a United Nations Security Council resolution authorizing sanctions against Tehran unless the regime suspends its nuclear program.

The announcement came after Secretary of State Condoleezza Rice met with top diplomats from France, Britain, China and Russia, all permanent members of the Security Council, along with envoys from Germany and the European Union.

Despite past Russian and Chinese reluctance to take a hard line with Iran, the diplomats said in a joint statement that they had “no choice” because Iran has not responded to an offer of incentives in exchange for stopping development of the nuclear program.

The nations involved will begin work at the U.N. next week drafting a resolution that sets a deadline for Iran to suspend uranium enrichment activities or face consequences, diplomats said.