The United States and France say they will push for a new round of international sanctions against Iran, after Tehran announced it would step up its uranium enrichment.
The U.N. Security Council has already imposed three sets of sanctions on Iran over its nuclear program, which Western countries suspect is being used for weapons purposes.
The American and French push for new sanctions was announced Monday in Paris, where U.S. Defense Secretary Robert Gates met with his French counterpart, Herve Morin. U.S. officials said they hope to bring a sanctions resolution to the Security Council this month, while France holds the rotating presidency.
Iran said earlier Monday it has told the U.N. nuclear agency of its plan to enrich uranium to higher levels, defying calls by world powers for a halt to enrichment.
Tehran says its nuclear program is for peaceful purposes, and that it needs uranium enriched to 20 percent to fuel a medical research reactor.
The U.N. had brokered a deal with a group of world powers calling for Tehran to ship its uranium abroad for enrichment and having it returned to Iran as reactor fuel. But Iran had given mixed signals about its willingness to accept the deal.