United Nations Secretary-General Kofi Annan has urged Iran to give a signal that it considers a package of incentives aimed at defusing a nuclear stand-off to be 'constructive'.
Speaking in Rome, he urged President Mahmoud Ahmadinejad to try and give any signal that he takes the incentives seriously and feels that they can be used as a basis for negotiations, even if they are seeking further clarification.
Mr Annan spoke after the United States stepped up pressure on Iran, warning it faced UN Security Council action for failing to respond swiftly enough to the package of incentives.
Foreign ministers of the world's top powers are meeting in Paris to decide how to handle Iran after Tehran said it needed more time to consider the 6 June offer.
France, Britain, Germany, the United States, China and Russia agreed last month on measures aimed at convincing Iran to abandon large-scale uranium enrichment, which produces fuel for power plants or weapons.
They have told Iran they want a clear response before this weekend's Group of Eight industrialised nations summit in Russia.
