Their upbeat verdicts could slow Washington's push for swift U.N. Security Council action to impose sanctions on Iran over its nuclear fuel program despite European misgivings about isolating the world's No. 4 oil supplier.

Seven hours of weekend talks in Vienna had been regarded as a last chance to explore a face-saving compromise before moves to impose sanctions after Iran ignored an August 31 Security Council deadline to stop enriching uranium.

"The meetings ... have been productive. We clarified some of the misunderstandings we had before" about Iran's 21-page reply to six world powers' offer of trade inducements to halt nuclear fuel work, Solana told reporters.

"We have made progress and we want to continue in that line and for that purpose we are going to meet again next week. These (talks) have been worth it," he said.

Larijani, standing beside Solana, said: "We have made constructive progress. We have reached common points of view on a number of issues. And as mentioned by Dr. Solana, many of the misunderstandings were removed. Our meetings will continue."

Solana was to brief leaders of the six powers on the results before they hold a conference call on Monday to discuss what to do next. Another round of talks could happen only after Solana returns from a visit to Africa on Wednesday.

Both sides declined to elaborate on the progress made, but an EU diplomat said earlier the crucial issue of timing for a suspension of uranium enrichment was addressed at the talks.

Solana had wanted to pin down Larijani on hints in Tehran's meandering response to the incentives package that it could curb enrichment as part of negotiations to implement the offer.

/Reuters/