European Union foreign policy chief Catherine Ashton says nuclear talks between Iran and world powers will "move to the next stage" in May.
After two days of talks in Vienna, Ashton said a new round of nuclear talks would start May 13. Diplomats have held three rounds of talks this year.
Iranian leader Ayatollah Ali Khamenei reiterated his support Wednesday for nuclear talks with world powers. But he also insisted Tehran would continue its atomic program.
Those involved in talks want to reach a permanent deal by the end of July that builds on an interim agreement reached last year.
Under the temporary pact, Iran agreed to curb its most sensitive nuclear activity, in exchange for limited sanctions relief from the group that includes the United States, Britain, China, France, Russia and Germany.
U.S. Secretary of State John Kerry has said Iran has the ability to produce enough material for one nuclear bomb in two months, even though Iran would not necessarily have the ability to deliver a weapon. He says there will be consequences if Iran continues to produce material at that rate.
Both sides have said they want to begin drafting a permanent agreement next month.