Talks in Berlin between Iran and the European Union on Tehran's nuclear program ended Wednesday evening and will resume Thursday.
EU spokeswoman Christina Gallach described Wednesday's meeting between Iran's top nuclear negotiator Ali Larijani and EU foreign policy chief Javier Solana as "very intense."
Speaking to reporters in Washington, U.S. Secretary of State Condoleezza Rice renewed U.S. support for Solana's talks with Iran. She said an agreement by Iran to stop enriching uranium would open doors for negotiations.
But she added discussions between Solana and Larijani will not go on "very much longer." The two have met on several different occasions.
In Tehran, Iran's President Mahmoud Ahmadinejad vowed his country would not give up the right to nuclear technology.
Iranian state media quoted him as saying demands from western nations for Iran to stop enriching uranium are what he called propaganda.
Iran ignored an August 31 U.N. Security Council deadline to halt uranium enrichment, which the West suspects is part of a program to develop nuclear weapons. Iran says it is pursuing nuclear technology only for peaceful purposes.
Some information for this report was provided by AFP, AP and Reuters.