VIENNA (Sputnik) � The talks on�Iran nuclear program, taking place in�Vienna, are progressing very slowly, German Foreign Minister Frank-Walter Steinmeier told reporters on�Thursday.�

Earlier in�the day, UK Foreign Secretary Philip Hammond said upon�his arrival to�Vienna there was no breakthrough yet in�the Iran nuclear talks.

"The negotiations are so difficult. They are not only very extended in�time, but�also very difficult. All i can assure you is that my impression is that all of�us here in�Vienna are seriously prepared to�come to�a result," Steinmeier said

He added that there are obstacles the sides were trying to�remove and the last steps toward�an agreement will be the most difficult.

Despite the difficulties, the minister expressed certitude that the discrepancies between�the sides would be overcome.

"I am optimistic that we will have a meeting with�ministers," Steinmeier pointed out.

In April, as�Iran and the P5+1 group, comprising Russia, China, France, the United Kingdom, the United States and Germany, signed a political framework deal, Tehran agreed to�cut back uranium enrichment and decrease its number of�centrifuges in�exchange for�sanctions relief.

At the center of�this last round�of talks in�Vienna between�the six world powers and Iran are the timing of�sanctions relief and the mechanisms to�ensure Tehran's compliance with�the agreement.

The date for�the ministerial meeting of�all the negotiating process's participants to�sign the final agreement has not been set yet.

By Sputnik