TEHRAN (FNA)- Head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi voiced his satisfaction with the ongoing trend of nuclear negotiations between Tehran and the world powers in Vienna, and said that there is still a strong possibility for striking a final agreement in the Austrian capital.

"There is a high chance for agreement in the Austrian capital," Salehi told reporters in Vienna on Friday.

He underlined that the negotiations are making progress as the two sides are doing their best to narrow down the differences.

Salehi's remarks came as diplomatic sources in Vienna on Thursday night cautioned that the western powers have toughened their stances after the US lost a self-imposed deadline for a deal with Iran and are raising even more demands from the Iranian team.

The source said the western parties to the talks with Iran, specially the US, have in the last few days raised excessive demands beyond earlier agreements, making the road to a draft final nuclear deal even more bumpy.

The source said Iran is determined to clinch a deal and it has shown much flexibility on this path, but the US-led West has been raising excessive demands and shows "fading respect for its earlier agreements with Iran".

"They have started psychological operations and are playing the blame game to make Iran surrender to their increasing demands or wait to be portrayed as the party to blame for the potential failure of the talks," the diplomat added.

The source also strongly rejected the allegations made by certain western media outlets that the Iranian team is referring the opposite sides' proposals or the draft text to Tehran to ask for permission, reiterating that "the� Iranian team of negotiators have been vested with full authority to strike a deal on behalf of the Islamic Republic of Iran based on the country's specified redlines, and does not need to refer anything to Tehran."

The diplomat strongly warned the western powers' approach in the last few days "is pushing the talks into a deadlock".

By Fars News Agency