Antony Blinken
Antony Blinken Reuters

US Secretary of State Antony Blinken said Wednesday that he was "not optimistic" about the prospects to revive the 2015 Iran nuclear deal.

Speaking to NBC News, Blinken said: “I would say simply that I’m not overly optimistic at the prospects of actually getting an agreement to conclusion, despite all the efforts we put into it and despite the fact that I believe … our security would be better off. We’re not there.”

Blinken's comments come after several reports that a final agreement in the negotiations in Vienna is close.

An agreement has appeared to be close at hand on several occasions during the talks' progress, but discussions stalled last month when Russia demanded guarantees that international sanctions imposed following its invasion of Ukraine would not negatively impact its trade with Iran.

Iran’s Foreign Minister Hossein Amir-Abdollahian said on Sunday that an agreement is “close” in negotiations to restore the 2015 nuclear deal (Joint Comprehensive Plan of Action or JCPOA) between Tehran and world powers.

“We are close to an agreement in the negotiations,” Amir-Abdollahian said during a phone conversation with UN Secretary-General Antonio Guterres, according to a statement by the Iranian Foreign Ministry.