Chancellor Angela Merkel on Tuesday reaffirmed Germany's readiness to back tougher sanctions against Iran if it fails to back down in the dispute over its nuclear ambitions. Before a weekend visit to US President George W. Bush's Texas ranch, Merkel also stressed her commitment to a diplomatic resolution of the issue. Germany, along with the five permanent members of the UN Security Council, has been at the forefront of efforts to address concerns over Iran's nuclear program. The Security Council has demanded that Teheran suspend uranium enrichment - a potential pathway both to generating nuclear power and creating the fissile core of warheads. Iran could face further sanctions if upcoming reports by the European Union and the International Atomic Energy Agency do not show improved Iranian cooperation. In her acceptance speech for the Leo Baeck Prize - the highest honor of Germany's Central Council of Jews - Merkel stressed "the special historic responsibility of Germany for the security and existence of Israel." "I am aware that, in view of the threat to Israel from Iran's nuclear program, these cannot remain empty words," she said. "We are looking, together with our partners, for a diplomatic solution," Merkel said. "Part of that is that Germany, if Iran does not give way, is prepared for further and tougher sanctions." Merkel said that she would discuss Iran, as well as prospects for peace between Israelis and Palestinians, during her meeting with Bush.