Iran’s national security chief has tweeted that “the powerless US president” is unable to give guarantees and without it the fate of the nuclear talks is clear.

In a series of tweets on Wednesday, Ali Shamkhani compared Iran’s current sanctions to conditions during the 1980s Iran-Iraq war when he said they were also calls for talks.

Iran’s top national security official added that during the war “Soldiers at the fronts were defending and now scientists will continue their legal nuclear activities”.

Iran has been enriching uranium this year to 20 and 60 percent purity, violating the terms of the Joint Comprehensive Plan of Action (JCPOA) and so far, not returning to multilateral nuclear talks that it left in June. Tehran says that since the United States and Europe have not honored their commitments under the JCPOA, it has a right to expand its nuclear program.

One of Iran’s demands is that President Joe Biden must provide guarantees that a future US president will not leave the agreement, as Donald Trump did in 2018. But if an agreement is not ratified by the US Senate as a treaty, no president can provide such a guarantee.

Shamkhani wrote that “the powerless US president is unable to provide a guarantee” and if the situation does not change “the fate of the nuclear talks is clear”.