Iranian Foreign Minister Mohammad Javad Zarif said Wednesday progress has been made in his talks with EU diplomatic chief Catherine Ashton over his country's disputed nuclear programme.

"We have made progress; we exchanged views during lengthy discussions that we have had in the last two days in Istanbul with Catherine Ashton," who represents world powers, said Zarif.

"Iran is determined to find a solution that respects the rights of the Iranian people and also clear up any misunderstandings about the sites of the Iranian nuclear programme," Zarif told reporters in Algiers.

"It's a matter of time, but also political will must be expressed to reach an agreement. I can assure you the other party has the political will to reach an agreement," he added.

Iran has consistently denied it is seeking nuclear weapons but wants an independent atomic energy programme.

Israel and lawmakers in the US Congress have repeatedly warned against lowering the pressure on the Islamic republic.

The next round of talks on resolving Western concerns will take place in Vienna on June 16-20.

Three days of meetings two weeks ago made no "tangible progress," as a July 20 deadline for a conclusive agreement looms on the horizon and major issues remain outstanding.

These reportedly include the scope of Iran's enrichment of uranium, which if further purified could be used to trigger a nuclear explosion, and its unfinished Arak research reactor, whose by-product waste could provide an alternative route to an atomic bomb.