Talks in Istanbul between world powers and Iran over Iran's nuclear programme have broken up without progress.
EU foreign policy chief Catherine Ashton, who led the international team, said she was disappointed by Iran's insistence on pre-conditions.
Baroness Ashton said it wasn't possible to embark on a discussion about practical ways forward to ease concerns about the purpose of the nuclear programme, which Iran says is peaceful.
Iran's chief negotiator, Saeed Jalili, says any kind of talks and co-operation need to be based on respecting nations' rights, including his country's right to nuclear technology.
