Iranian Foreign Minister Hossein Amir-Abdollahian has told NPR that the guarantee issue is very important to Iran in negotiations on the revival of the 2015 nuclear deal.

Tehran has demanded U.S. assurances that no future American president would abandon the deal as former U.S. President Donald Trump did in 2018, Reuters reported. 

"The current situation was created by former U.S. President Donald Trump, and incumbent U.S. President Joe Biden has, like Trump, imposed on average one or two sanctions against Iran on a monthly basis, during its indirect participation in the nuclear negotiations over the past months," Amir-Abdollahian told NPR in a recent interview, the text of which was released by the Iranian Foreign Ministry on its website on Thursday.

However, the agreement draft the United States sent to Iran contained a large number of ambiguities, the Iranian foreign minister said, adding Iran is "serious about an agreement, but we don't know if the American side has the necessary realism and courage to make its decision."

On August 31, Amir-Abdollahian also highlighted the importance of guarantees at a press conference held in Moscow, where he said Iran needs guarantees "from the other party to have a sustainable deal."

In response to those comments, White House national security spokesman John Kirby said the U.S. side was "cautiously optimistic."

"We are also pragmatic and clear-eyed and we realize that there's still gaps, and we're trying to close those gaps in a good-faith way, negotiating through appropriate channels and not through the public," Kirby said. 

Talks on the revival of the deal began in April 2021 in Vienna but were suspended in March this year because of political differences between Iran and the United States. The latest round of the nuclear talks was held in the Austrian capital in early August after a five-month hiatus.

Iran signed the original nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), with world powers in July 2015, agreeing to curb its nuclear program in return for removing sanctions on the country.

However, Washington quit the agreement and reimposed unilateral sanctions on Tehran, prompting the latter to drop some of its commitments under the pact.

"We maintain that diplomacy is the solution and are serious and persistent about reaching a robust and lasting agreement," Amir-Abdollahian said.

(With input from agencies)