In a rare English-language joint statement, European Union foreign policy chief Catherine Ashton and Iranian Foreign Minister Javad Zarif said two days of multilateral discussions on Iran's nuclear program were "substantive and forward-looking."
Western powers have been cautiously optimistic with rhetoric coming from Tehran after Iranian President Hassan Rouhani took office in August. The U.S. government said it was willing to consider Iran's right to a nuclear program provided it had assurances it wouldn't develop a weapon.
Iran's enrichment of uranium to 20 percent purity was characterized as a "red line" by Tehran ahead of this week's talks in Geneva.
Mansour Haqiqatpour, deputy chairman of the foreign policy committee in Iran's parliament, the Majlis, said Thursday lawmakers were holding to the enrichment line.
"We hope that the negotiations will produce good results through recognition of Iran's [uranium] enrichment right and the removal of sanctions," he was quoted by state-funded broadcaster Press TV as saying.
Uranium enrichment to 20 percent purity is considered a key technological step on the path to a weapon.
A high-ranking U.S. official, speaking to reporters Wednesday on background, sidestepped questions on enrichment.
"We are very clear that Iran must not acquire a nuclear weapon," the official said.