A fourth round of high-level talks aimed at returning the United States to a landmark 2015 nuclear deal between world powers and Iran have begun in Vienna.
Washington withdrew from the agreement in 2018 after then-President Donald Trump said the pact needed to be renegotiated.
Under the deal, Iran had pledged to curb its nuclear activities in exchange for an easing of international sanctions. The administration of former President Donald Trump reimposed the sanctions on the Islamic republic in an unsuccessful attempt to bring Tehran into new talks.
Iran reacted by stepping up violations of the accord -- which is intended to prevent the country from obtaining nuclear weapons -- by enriching uranium to a greater purity and stockpiling more than allowed, and introducing more advanced centrifuges.
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It also pushed the remaining parties in the deal -- France, Britain, Russia, and China -- for economic relief.
U.S. President Joe Biden has said he wants to rejoin the deal, known as the Joint Comprehensive Plan of Action, or JCPOA, but that Iran needs to return to compliance.
The current talks, which restarted on May 7, are focused on creating a road map for Washington to lift sanctions on Iran and for Tehran to reinstate restrictions on its nuclear program that were laid out in the original deal.
On the eve of the new round of talks, a senior U.S. administration official laid out all of the steps Washington is prepared to take in order to rejoin the nuclear deal.
The official, who spoke to reporters on a conference call on May 6, said Iran shouldn't expect major new concessions, and success or failure now depends on Iran making the political decision to accept those concessions and to return to compliance with the accord.
Meanwhile, U.S. Secretary of State Antony Blinken said in an interview it was unclear whether Iran is prepared to make the decisions necessary to return to full compliance with the agreement.
"They unfortunately have been continuing to take steps that are restarting dangerous parts of their program that the nuclear agreement stopped. And the jury is out on whether they're prepared to do what's necessary," he said in an interview broadcast on May 6 on NBC.
Iranian Deputy Foreign Minister Abbas Araqchi, the head of Iran's delegation, said after the third round of talks ended on May 1 that Tehran stands by its demand for the United States to lift sanctions across a range of sectors, including oil, banking, and most individuals and institutions.
In parallel with the nuclear talks, Iranian media reported last weekend that there was an agreement between Tehran and Washington for the release of prisoners held by each side.
Washington and London have dismissed or downplayed the reports, as well as others that have said the United States is considering unfreezing some Iranian assets.
Because the United States is currently out of the deal, there is no American representation at the talks. Diplomats from the participating countries involved are shuttling between the Iranian side and a delegation from Washington elsewhere in Vienna.
Heading into the talks, Russian delegate Mikhail Ulyanov tweeted that he saw positive signs from the Iranian minister's statements.
"The head of the Iranian delegation is cautious in his assessment of the current state of affairs at the Vienna talks (very similar to assessments of the U.S. colleagues)," he tweeted.
'But both #Iran and #US refrain from pessimistic conclusions. This seems to be not a bad sign as of the moment.'
With reporting by AP, Reuters, AFP, and dpa
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