Negotiations to revive Iran's 2015 nuclear agreement with world powers will fail unless U.S. President Joe Biden can guarantee that Washington will not again abandon the pact, the head of Iran's Supreme National Security Council said on Wednesday.

"The U.S. President, lacking authority, is not ready to give guarantees. If the current status quo continues, the result of negotiations is clear," Ali Shamkhani said in a tweet.

Iran is expected to give an exact date this week for the resumption of talks with the powers, scheduled for end of November according to Iranian top nuclear negotiator Ali Bagheri-Kani.