(Adds quotes, detail, background) HEILIGENDAMM, Germany, June 8 (Reuters) - French President Nicolas Sarkozy said on Friday the international community needed to signal tougher sanctions to Iran over its disputed nuclear programme. The U.N. Security Council has imposed two rounds of sanctions against Tehran since December and the Group of Eight industrialised nations said on Friday it would back "further measures" against Iran if it did not comply with U.N. demands that it suspend its uranium enrichment programme. "On Iran, it seems to me that there is a large community of views of China, of Russia and of the United States of America to push the Iranian leaders to return to the negotiating table," Sarkozy told a news conference at an annual G8 summit in Germany. "I think we will have to send a message of firmness, certainly of toughening sanctions," Sarkozy said. The existing sanctions were imposed on Iran for its failure to convince world powers that it is not developing nuclear weapons under the cover of a civilian atomic programme. Iran says it only wants to harness nuclear energy to generate electricity.
