Senior Iranian and Western envoys have indicated they may have made progress in trying to break a deadlock over Tehran's defiance of a UN demand to suspend uranium enrichment.
In announcing additional talks in two weeks neither European Union foreign policy chief Javier Solana nor Ali Larijani, Iran's top international negotiator, revealed details of their two meetings yesterday.
But an official said the two touched on having talks of what would constitute a suspension. A more flexible definition of a freeze acceptable to both sides is "the key issue," said the official.
There was also mention of a "double time out" - a simultaneous freeze of Iranian atomic activities in exchange for a commitment not to impose new UN sanctions, said the official.
Mr Larijani described the discussions as "pleasant", and Mr Solana spoke of a "very constructive dinner," adding that talks "will continue tomorrow and in the coming weeks also".