Berlin ? Negotiators for Iran and the European Union held five hours of “very intense” talks Wednesday over Iran’s disputed nuclear program and planned to meeting again today, officials said.

EU foreign policy chief Javier Solana and chief Iranian nuclear negotiator Ali Larijani went into their meeting at a Foreign Ministry facility by the side of Lake Tegel on the outskirts of Berlin without making statements to reporters.

German Foreign Minister Frank-Walter Steinmeier, who was not participating in the Berlin talks, said he was optimistic that progress could be made.

Solana would report back to the six countries trying to persuade Iran to give up its program to enrich uranium, he said, “and then it will be decided together if there are conditions for a return to the negotiating table.”

But in Tehran, Iran’s hard-line president Mahmoud Ahmadinejad said his country won’t give up “one iota” of its right to pursue a peaceful nuclear program.

Ahmadinejad said the U.S. and its European allies want to force Iran to suspend uranium enrichment but won’t succeed.