European and Iranian officials meeting in Berlin this week say they have reached no breakthrough on the impasse over Iran's nuclear program. Both sides say they made progress Wednesday and Thursday, before the talks ended.

European Union foreign policy chief Javier Solana and Iran's top nuclear negotiator, Ali Larijani, offered upbeat remarks to reporters after talks in Berlin, the first between the two officials in more than two weeks.

Solana told reporters at a news conference Thursday that the two sides had made progress. Larijani struck a similar tone, saying they had arrived at some positive conclusions.

Just what those conclusions are remains unclear. Iran failed to meet an August 31 deadline set by world powers to stop its nuclear enrichment activities, which the United States and some other nations fear may be aimed at producing a bomb. Tehran insists its nuclear program is for peaceful purposes.

The six countries trying to persuade Iran to return to the negotiating table are divided over whether to push for U.N. sanctions against Iran, if negotiation efforts fail. China, Russia, and France are reluctant to resort to sanctions; the United States supports them.

But Michael Emerson, an analyst at the Center for European Policy Studies in Brussels, says divisions exist in Iran as well.

"Within Iran we do know that there's really a very important set of divergences between different parts of the political system, from the supreme leader down to people in the government and other important personalities. And I guess the debate within Iran is one of judging what the costs to them are going to be of completely breaking off with the EU negotiators," he noted.

Iran's president, Mahmoud Ahmadinejad, continues to insist Iran will continue its nuclear-enrichment program. Last week at the United Nations in New York, President Bush said he is willing to give diplomacy more time before pushing for U.N. sanctions.

The next opportunity for a diplomatic solution will be next week, when Solana and Larijani are expected to be back in contact.