A nuclear-armed Iran would be a "game-changer for the region," allowing the Islamic republic to meddle through extremist proxies, intervene in Iraq and threaten oil supplies, the Democrat told about 250 voters at a meeting here.

"My job as president is to make sure we are tightening the screws on Iran diplomatically... to get sanctions in place so that Iran starts making a different calculation," the Illinois senator said.

"And we've got to do that before Israel feels like its back is against the wall."

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.