Iran has further scaled back its commitments to the 2015 nuclear deal by raising its enrichment levels beyond what was agreed in the deal, according to the United Nations' nuclear watchdog which on Monday confirmed claims from local media.
"[International Atomic Energy Agency] Director General Yukiya Amano has informed the IAEA Board of Governors that Agency inspectors on 8 July verified that Iran is enriching uranium above 3.67%," an IAEA spokesman said.
A report to member states obtained by Reuters said the agency had verified the enrichment level using online enrichment monitors and samples had also been taken on Monday for analysis.
IRNA news quoted atomic agency spokesperson Behrouz Kamalvandi on Monday as saying the 3.67% enrichment level agreed in the deal had been breached.
He later told the semi-official ISNA news agency that enrichment had in fact reached 4.5%.
The announcement signals a growing challenge to escalating US sanctions pressure.
China criticizes US strategy
China criticised the US on Monday for "bullying" Iran, saying the reintroduced sanctions were the cause of the crisis.
Chinese Foreign Ministry spokesperson Geng Shuang said: "The maximum pressure of the United States on Iran is the source of the Iranian nuclear crisis."
In a news conference on Sunday, senior Iranian officials said Tehran would keep reducing its commitments every 60 days, unless signatories of the pact moved to protect it from US sanctions, but they left the door open to diplomacy.
Before the deal was sealed, Iran produced 20% enriched uranium needed to fuel its Tehran reactor and the level of enrichment for its southern Bushehr nuclear power plant was 5%.
"We will enrich uranium based on our needs ... right now we don't need to enrich uranium needed for Tehran reactor," said Behrouz Kamalvandi, Iran's Atomic Energy Organization spokesman.
"We will enrich uranium to the level that is needed for the Bushehr reactor."
But the measures are "reversible" if the European signatories of the pact fulfill their obligations, Foreign Minister Mohammad Javad Zarif tweeted, also on Sunday.
Britain, one of Washington's main allies, was drawn deeper into the confrontation last week when its Royal Marines seized an Iranian tanker entering the Mediterranean off Gibraltar over separate sanctions against Syria.
"Iran is neither a member of the EU nor subject to any European oil embargo. Last I checked, EU was against extraterritoriality. UK's unlawful seizure of a tanker with Iranian oil on behalf of #B_Team is piracy, pure and simple," Iran's Foreign Minister Mohammad Javad Zarif tweeted on Monday, referring to the Trump administration as "B team".
'Carefully calibrated breaches'
Robin Niblett, Director of Chatham House, a London-based foreign policy think-tank, told Euronews:
"Iran is trying to re-build leverage for the post-JCPOA negotiation with the US." [The Iran nuclear deal is formally called the Joint Comprehensive Plan of Action or JCPOA.]
"Its breaches of the 2015 agreement are carefully calibrated. Step 1. Exceed prescribed amount of uranium enriched to 3.65% purity. Now. Enrich to 5% for Tehran civil reactor. Plenty of steps to go," the expert continued.
Under the pact, Iran can enrich uranium to 3.67% fissile material, well below the 20% it was reaching before the deal and the roughly 90% suitable for a nuclear weapon.
Macron steps in
A top diplomatic advisor to French President Emmanuel Macron will travel to Iran on Tuesday and Wednesday to try to de-escalate tensions between Tehran and the US, a French presidential official said on Monday.
US President Donald Trump on Monday spoke to Macron about Iran's threat to ramp up enrichment of uranium, the White House said.
"They discussed ongoing efforts to ensure that Iran does not obtain a nuclear weapon and to end Iran's destabilizing behaviour in the Middle East," a White House spokesman said in a statement.
Macron condemned on Sunday the Iranian decision to enrich uranium above limits agreed upon in 2015, a move he qualified of "violation" of the agreement, an official of the presidency told Reuters.
The French president reiterated the deadline of July 15 to resume dialogue between the parties, the official said, without elaborating on what would happen after that date.
But the Iran nuclear deal dispute resolution mechanism will not be triggered for now. "It's not an option at this moment," said the source at President Macron's office.
The French presidency's comments come just a day after Macron said he and Iran's President Hassan Rouhani had agreed to seek conditions for a resumption of dialogue on the Iranian nuclear question by July 15.
'Reverse all activities'
London and Berlin have also expressed concerns over Iran's latest announcement.
"We strongly urge Iran to stop and reverse all activities inconsistent with its commitment," a German foreign ministry spokesperson said, adding that Berlin was in touch with London and Paris to decide on the next steps.
The British Foreign Office issued a similar statement, saying that "while the UK remains fully committed to the deal, Iran must immediately stop and reverse all activities inconsistent with its obligations" and that it was in contact with the other European signatories of the deal.
Israel says Iran 'moving towards potential bomb'
Reacting to the announcement, Israeli Prime Minister Benjamin Netanyahu said on Sunday the announced increase of uranium enrichment by Iran was an extremely dangerous move and he again called on Europe to impose punitive sanctions on Tehran.
"I call on my friends, the heads of France, Britain and Germany - you signed this deal and you said that as soon as they take this step, severe sanctions will be imposed - that was the Security Council resolution. Where are you?" Netanyahu said.
If anyone of the three European parties to the accord believe Iran has violated the agreement, they can trigger a dispute resolution process that could, within as few as 65 days, end at the UN Security Council with a reimposition of UN sanctions on Tehran.
The other remaining signatories, Russia and China, are allies of Iran and unlikely to make such a move.
"The enrichment of uranium is made for one reason and one reason only - it's for the creation of atomic bombs," said Netanyahu, a strong opponent of the 2015 agreement.
Long-tense relations between Tehran and Washington took a turn for the worse in May 2018 when US President Donald Trump pulled out of the 2015 nuclear deal reached before he took office, and reimposed sanctions.