The EU's foreign policy chief has said that misunderstandings about Iran's nuclear programme have been cleared up, in talks with its chief negotiator.
Mr Larijani and Mr Solana say they will meet again next week
Javier Solana and Ali Larijani said progress had been made in a second day of talks to find a compromise to avoid UN sanctions against Iran.
The two officials said they would meet again next week.
But Iran has ruled out accepting any preconditions for talks and dismissed calls to suspend uranium enrichment.
Suspension was an issue in the past and Iran would not take a step back, said Foreign Ministry spokesman Hamid Reza Asefi.
Iran says its nuclear programme is solely for power generation.
Mr Solana said he had worked for more than seven hours with Mr Larijani at the federal chancellory in the Austrian capital, Vienna.
"We have clarified some of the misunderstandings that existed before. We have made progress that we want to continue," he said.
The US on Friday said it hoped the UN Security Council would begin work on a draft resolution authorising sanctions against its long-time foe next week, after Iran ignored a UN-imposed deadline to suspend enrichment.
But other powers have expressed doubt that sanctions would prove effective against the world's fourth-largest oil exporter.