"I think that at this point in time to have also the USA open a channel of communication with Iran would be worth thinking about ... on everything," said Solana. He and Larijani held talks in Ankara on Wednesday and Thursday. "We have to see how much the USA are ready to engage," he said.

These were their first face-to-face meetings since the UN Security Council imposed a second round of limited sanctions on Iran in March over Tehran's refusal to halt uranium enrichment. More talks are scheduled in two weeks.

Solana, in his talks with Larijani, represented the five permanent members of the Security Council plus Germany. He said on Friday that the talks were "constructive conversations."

All sides need to be tenacious, says Solana

"They were constructive in the sense that it was some potential motion that we have to see if we can exploit in a next meeting we'll have in about ten days," he said. "I don't want to say at all that the difficulties are overcome, we have many important hurdles that have to be overcome, but we have to be tenacious."

Asked whether Larijani and Iran's supreme leader Ali Khamenei were ready to speak to the United States, based on his conversations with Larijani, Solana replied: "I say without any hesitation, yes."

Solana was speaking Friday after a Brussels Forum organised by the German Marshall Fund of the United States.

Assistant under secretary of state Dan Fried, who was also at the Brussels conference, said he was not in a position to announce any change in US policy. "I'm not going to announce any change to it," he said.

Solana and Rice to discuss tactics

"We've been in a far better place working with Europe about Iran then when we were quarelling with Europe about Iran, which was the case a couple of years ago," he added. "The question of tactics in the way ahead is one (US Secretary of State) Condoleezza Rice and Solana will be discussing in the days ahead. Our position at the moment is well known."

Washington, which broke off diplomatic relations with Iran in 1980, accuses Iran of wanting to develop nuclear weapons -- which Tehran denies -- and of supporting insurgents in Iraq.

Rice may meet Iranian Foreign Minister Manouchehr Mottaki at a conference on security in Iraq in Egypt on May 3-4 but Iran has yet to confirm whether it will attend.

US President George W. Bush has said Rice, who is set to attend the conference, "could" hold bilateral talks with Mottaki should Iran decide to participate. But he said that there would be no one-to-one talks outside such a context or discussions about Tehran's nuclear program.