TEHRAN (FNA)- A senior advisor to the Iranian president underlined that Tehran has long time ago taken its hard decision, adding that now it is the West's turn give up the policy of pressures and sanctions.

"Iran has taken its tough decision long time ago," Cultural Advisor to the Iranian president Hessameddin Ashena wrote on his Facebook page on Saturday.

"Now its time for others to leave the sanctions and learn the language of respect," he added.

His remarks came after Iranian Foreign Minister Mohammad Javad Zarif complained that change in the stances of the Group 5+1 (the US, Russia, China, France and Britain plus Germany) and their excessive demands have prevented attainment of a nuclear deal, and called on the western powers to make up their minds and choose between striking a final deal and keeping the sanctions.

"We have reached a stage now that the other side should decide if it is seeking an agreement or pressure; we have said many times that agreement and pressure cannot come together and one of them should be chosen," Zarif, also Iran's top negotiator in the talks with the world powers, told reporters in Vienna on Friday.

He reiterated that if the other side shows political will and inclination for a balanced and good deal it will be achievable.

Zarif, however, said that unfortunately the other side is showing change in stances and raising excessive demands which make the conditions difficult, adding, "We are doing our best as Supreme Leader (of the Islamic Revolution Ayatollah Seyed Ali Khamenei) and other Iranian officials have said many times we are looking for a good deal and we will continue the negotiations; we have never left the negotiations and we will not in future."

Late on Thursday night, diplomatic sources in Vienna 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