US Secretary of State Mike Pompeo has said the top secret documents Israel claims to have obtained on Iran’s nuclear programme show Tehran has lied.
Mr Pompeo said the information indicates that a nuclear deal signed between Iran and six world powers in 2015 was not built on good faith.
President Trump has long signalled his desire to abandon the deal and is due to make a decision in the coming weeks.
Iran has described the documents as a “rehash of old allegations”.
On Monday, Israeli Prime Minister Benjamin Netanyahu revealed what he said were thousands of “secret nuclear files” that proved that Iran had once covertly pursued nuclear weapons.
He said it went against a 2015 agreement in which Iran said it would curb its nuclear energy programme in return for the lifting of sanctions.
Tehran has maintained that it has only been pursuing nuclear energy.
Mr Netanyahu, however, accused Iran of conducting a secret weapons programme until 2003 codenamed “Project Amad”. He claimed Iran continued to pursue nuclear weapons knowledge after Project Amad was shuttered.
Iran’s Foreign Minister Javad Zarif said the move by Mr Netanyahu was a “childish” stunt to influence Mr Trump’s decision on whether the US should stick with a nuclear deal with Iran.
Mr Trump, who has been vocal about his exception to the Obama-era deal, said he had viewed part of Mr Netanyahu’s presentation and said the situation was “not acceptable”.
He said he would make a decision on whether to retain the deal on or before 12 May.
A White House statement said there were “new and compelling details” in Mr Netanyahu’s material.
What did Pompeo say?
“The documents obtained by Israel from inside Iran show beyond any doubt that the Iranian regime was not telling the truth,” Mr Pompeo said in a statement.
“We assess that the documents we have reviewed are authentic,” he said, adding: “Iran hid a vast atomic archive from the world and from the International Atomic Energy Agency (IAEA) – until today.”
Mr Pompeo also warned that the US was now “assessing what the discovery of Iran’s secret nuclear files means for the future”.
What ‘proof’ did Netanyahu produce?
Speaking in English from Israel’s defence ministry in Tel Aviv, Mr Netanyahu showed off what he said were “exact copies” of documents obtained by Israeli intelligence from a secret storage facility in Tehran.
There were, he said, 55,000 pages of evidence and a further 55,000 files on 183 CDs relating to Project Amad.
The project, he said, had had the explicit goal of producing five warheads, each with the yield of 10 kilotonnes of TNT.
“These files conclusively prove that Iran was brazenly lying when it said it never had a nuclear weapons programme.”
The files had been shared with the US, Mr Netanyahu said, and would be submitted to the IAEA.
A 2007 US National Intelligence Estimate assessed “with high confidence” that Iran did have a nuclear weapons programme up until 2003 but that Iran had stopped it after its discovery.
On Monday the Israeli prime minister argued the existence of the alleged files proved Iran had been “secretly storing Project Amad material to use at a time of its choice to develop nuclear weapons”.
How is the 2015 deal meant to work?
The agreement signed between Iran, the US, China, Russia, Germany, France and Britain lifted crippling economic sanctions in return for curbs on Tehran’s nuclear programme.
There had been fears that Iran would use the programme to create a nuclear weapon.
Under the deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), Iran is committed to slashing the number of its centrifuges, which are machines used to enrich uranium.
It is also meant to cut its stockpile of enriched uranium drastically and not enrich remaining uranium to the level needed to produce nuclear weapons.
The number of centrifuges installed at Iran’s Natanz and Fordo sites was cut drastically soon after the deal while tonnes of low-enriched uranium were shipped to Russia.
Furthermore, monitors from the IAEA have been able to carry out snap inspections at Iranian nuclear sites.
How dangerous is the enmity between Israel and Iran?
Tension between the long-standing enemies has grown steadily since Iran built up its military presence in Syria, Israel’s north-eastern neighbour.
Iran has also been accused of supplying weaponry to Lebanese Shia Muslim militant group Hezbollah, an enemy of Israel, and also smuggling arms to Palestinian militants.
Mr Netanyahu has long vowed to stop Iran from strengthening its military presence in Syria.
On Sunday night, a wave of unclaimed air strikes on targets in Syria reportedly killed a number of Iranians.
Sites allegedly linked to a covert Syrian chemical weapons programme were bombed by Western nations earlier this month.
Israel has also carried out, or is believed to have carried out, dozens of air strikes on facilities in Syria used by Iranian forces.