The United States has warned that time is running out for a "strict return" to the frayed nuclear deal at the center of negotiations between Iran and world powers.
Secretary of State Antony Blinken's injunction came after Iran's new hard-line president, Ebrahim Raisi, pushed back on September 8 against a confidential report by the UN's nuclear watchdog accusing Tehran of blocking inspectors' access to atomic sites.
Raisi told European Council President Charles Michel by phone that Iran's "serious cooperation with the International Atomic Energy Agency is a clear example of Iran's will to be transparent about its nuclear activities," according to a statement from Raisi's office.
The European Union is mediating ongoing efforts between Iran and world powers to revive the 2015 nuclear deal that has been deteriorating since the United States withdrew from it three years ago.
The diplomatic riposte follows news of a confidential quarterly report from the International Atomic Energy Agency (IAEA) accusing Iran of blocking access to some of its nuclear sites for inspectors. The report also said Tehran continues to boost its stocks of uranium enriched above the percentage allowed in the 2015 accord.
"I'm not going to put a date on it, but we are getting closer to the point at which a strict return to compliance with the JCPOA [Joint Comprehensive Plan of Action] does not reproduce the benefits that that agreement achieved," Blinken said alongside German Foreign Minister Heiko Maas in response to a reporter's question during a visit to Germany.
Maas said that he had telephoned recently installed Iranian Foreign Minister Hossein Amir-Abdollahian to urge Tehran to "return more swiftly to the negotiating table."
Berlin expects Tehran to support the results so far from the Vienna negotiations but regards the delay in the EU-mediated talks signaled by Tehran as "far too long," Maas added.
Envoys from the United States and Russia, which is also a signatory to the deal, gathered in Moscow on September 8 for two days of talks expected to focus on the Iran deal.
Russian Deputy Foreign Minister Sergei Ryabkov said he was scheduled to meet with U.S. envoy Robert Malley "for a rather long time in order to discuss the whole situation and look ahead," the Russian diplomat told TASS news agency on September 8, when the first meeting was to be held.
"There are many problems, and, frankly speaking, now is one of those moments when it's extremely important not to make a mistake," Ryabkov said.
Reuters quoted a U.S. official as saying on condition of anonymity that the focus of the trip "will be on nuclear diplomacy with Iran and where we go from here."
The State Department announced earlier that Malley would travel to Moscow and Paris from September 7-10 to consult with Russia and European partners on "the need to quickly reach and implement an understanding on a mutual return to compliance" with the so-called JCPOA.
Former U.S. President Donald Trump withdrew from the accord in 2018 and reimposed tough sanctions that have crippled Iran’s economy.
Iran responded by gradually breaching its commitments under the deal.
Six rounds of talks on reviving the accord were held in Vienna between April and June to bring Tehran and Washington back into compliance. The talks have since stalled as Raisi took up the presidency in Tehran, but the parties to the original agreement are seeking to begin a new round in Vienna.
The IAEA in its recent report said Tehran had "seriously undermined" its inspectors at nuclear sites.
Raisi on September 8 fired back that "Of course, if the IAEA has a nonconstructive approach, it's unreasonable to expect a constructive response from Iran."
He added, "What's more, nonconstructive actions of course upset the negotiation process."
Under the 2015 deal between Iran and Britain, France, Germany, China, Russia, and the United States, Tehran agreed to curb its nuclear activities in exchange for sanctions relief.