Tehran, April 9 (IANS): Iranian supreme leader Ayatollah Ali Khamenei on Thursday said the appreciation for nuclear negotiating team was pointless, saying the other side is known for back-pedalling on its commitments.

"It is pointless to congratulate me and others at this point as the other side which is known for back-pedalling on its commitments may want to corner our country when it comes to the details of the negotiations," Press TV quoted Supreme Leader Ayatollah Ali Khamenei.

"Everything lies in the details," said Khamenei.

"So, it is suggested that what has been done so far cannot ensure a final deal," Khamenei noted.

"What has been done so far neither guarantees the clinching of an agreement itself and its contents, nor ensures that the negotiations would proceed to the end."

The Iranian leader said he had "never been optimistic about negotiations with the US", but that he has "supported and would support the negotiators" in the current talks.

He underlined that any deal would have to "ensure the interests and dignity of the Iranian nation".

Iran and P5 1 group of major world powers -- Russia, China, France, Britain, the US plus Germany -- along with officials from the European Union reached a mutual understanding on Tehran's nuclear programme after eight days of marathon talks in Lausanne, Switzerland, last week.

The two sides will now work on drawing up a final accord by the end of the self-imposed June 30 deadline.