TEHRAN – A top Iranian security official said on Monday that the success of the Vienna talks on the restoration of a 2015 nuclear deal depends on the U.S. political determination.

Nuclear negotiations in Vienna have reached a stage where “the outcome can be announced without guesswork,” Secretary of Iran’s Supreme National Security Council Ali Shamkhani tweeted. The U.S. political decision on whether to accept the requirements conducive to the conclusion of “a credible and lasting deal” based on the principles in the 2015 nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), he noted.

Iran signed the JCPOA with world powers in July 2015. However, former U.S. President Donald Trump pulled Washington out of the agreement in May 2018 and reimposed unilateral sanctions on Iran, which prompted the latter to drop some of its nuclear commitments one year later and advance its halted nuclear programs.

Since April 2021, eight rounds of talks have been held in the Austrian capital between Iran and the remaining JCPOA parties, namely Russia, China, France, Britain and Germany, to revive the landmark deal. The United States, which has been indirectly involved in the Vienna negotiations, has said it has until the end of February to resuscitate the 2015 nuclear pact, or the United States will launch “aggressive efforts” against Iran.