Senior Iranian cleric and former President Akbar Hashemi Rafsanjani says a deadline will not help in nuclear talks with Iran, and urged the West to give negotiations a chance.

Mr. Rafsanjani spoke during a Friday prayers sermon broadcast live on state radio.

His comments come as the United States warns Iran that time is running out to respond to proposals by the European Union and the United Nations Security Council to resolve the nuclear standoff.

Germany and the five permanent members of the Security Council (Britain, France, Russia, China and the United States) gave Iran two weeks to respond to an incentives package discussed last Saturday at talks in Geneva or risk another round of sanctions.

Iranian leaders have repeatedly said they will not suspend uranium enrichment, and on Wednesday, President Mahmoud Ahmadinejad insisted Iran will continue its nuclear program.

The closed-door talks in Geneva were the first to be attended by a senior U.S. envoy, Under Secretary of State William Burns.

Until now, the Bush administration had insisted on shunning nuclear talks with Iran until it stops enriching uranium.

Iranian and European Union negotiators have agreed to meet again in two weeks for more talks.

Earlier this week, U.S. Secretary of State Condoleezza Rice said Iran could face more sanctions if it does not meet the two-week deadline.

Iran is already under three sets of U.N. sanctions because of its refusal to halt uranium enrichment.

The United States and its Western allies have accused Iran of working to produce a nuclear weapon. Iran says its nuclear program is peaceful.  

Highly enriched uranium can be used to build a nuclear weapon.

Some information for this report was provided by AP and Reuters.