The United States obtained intercepted communication between senior Iranian officials discussing the US military strikes on Iran’s nuclear programme and remarking that the attack was less devastating than they had expected, said four people familiar with the classified intelligence.

The communication, intended to be private, included Iranian government officials speculating as to why the strikes directed by US President Donald Trump were not as destructive and extensive as they had anticipated, these people said.

It is the latest preliminary information offering a more complicated picture than the one conveyed by the President, who has said the operation “completely and totally obliterated” Iran’s nuclear programme.

The Trump Administration did not dispute the existence of the intercepted communication, which has not been previously reported, but strenuously disagreed with the Iranians’ conclusions and cast doubt on their ability to assess the damage at the three nuclear facilities targeted in the US operation.

“It’s shameful that the Washington Post is helping people commit felonies by publishing out-of-context leaks,” said White House press secretary Karoline Leavitt.

“The notion that unnamed Iranian officials know what happened under hundreds of feet of rubble is nonsense. Their nuclear weapons programme is over.”

Analysts broadly agree that the strikes involved immense US firepower, including 13,610kg bunker-buster bombs and Tomahawk cruise missiles, that severely damaged the nuclear facilities in Fordow, Natanz and Isfahan.

But the extent of the destruction and how long it may take Iran to rebuild has been hotly debated amid reports that Iran moved its stockpiles of highly enriched uranium before the strike and that the explosions sealed off the entrance to two of the facilities but did not collapse their underground buildings.

When asked about the intercepted communication, a Trump Administration official said the Iranians were “wrong because we’ve destroyed their metal conversion facility. We know that our weapons were delivered precisely where we wanted them to be delivered and they had the effect that we wanted.”

During classified congressional briefings, CIA Director John Ratcliffe told lawmakers that several key nuclear sites were completely destroyed, including Iran’s metal conversion operations, a US official said.

The facility, which is key to building a bomb’s explosive core, would take years to rebuild, the official said. Ratcliffe also said the US intelligence community assesses that the “vast majority” of Iran’s enriched uranium is “likely buried at Isfahan and Fordow”.

After the Washington Post sought comment from the Office of the Director of National Intelligence, a senior US intelligence official said that “one slice of signals intelligence on its own does not reflect the full intelligence picture”.

“A single phone call between unnamed Iranians is not the same as an intelligence assessment, which takes into account a body of evidence, with multiple sources and methods,” this official said.

Intercepted phone calls, emails and other electronic communications, known as signals intelligence, are among the most powerful tools in US spy agencies’ arsenal and often make up the majority of intelligence in Trump’s daily intelligence briefing.

But signals intelligence also has limitations, as overheard snippets of conversations sometimes lack context and must be paired with other information for a fuller picture of events.

Trump has been furious about news coverage that has deviated from his claims about the bombing mission, which preceded a ceasefire between Iran and Israel ending 12 days of hostilities.

“The Democrats are the ones who leaked the information,” he wrote on Truth Social, referring to a preliminary assessment from the Pentagon’s Defence Intelligence Agency that Trump’s intervention likely set back Iran’s nuclear programme by months, not years. “They should be prosecuted!”

Trump also cast doubt on reports that the uranium stockpile was moved, saying during a prerecorded interview with Fox News that is scheduled to air today: “I don’t think they did, no. It’s very hard to do; it’s very dangerous to do … they didn’t know we were coming until just then.”

The Defence Intelligence Agency finding was based on information available roughly 24 hours after the strike and concluded that some of Iran’s centrifuges, used to enrich uranium that could be used in a nuclear weapon, remain intact.

Nuclear facilities in Iran. Photo / Getty Images

The Trump Administration has criticised some media outlets for failing to note that the DIA report, which it deems “low confidence”, cautions that a full battle damage assessment requires “days-to-weeks to accumulate the necessary data to assess effects on the target system”.

However, the Administration has not waited to assert its own sweeping conclusions that the strikes have set back Iran’s programme for “years”.

Defence Secretary Pete Hegseth, who briefed reporters on the operation alongside the Joint Chiefs of Staff chairman, General Dan Caine, said Trump “directed the most complex and secretive military operation in history - and it was a resounding success”.

On Capitol Hill, disagreements about the effectiveness of the strikes remained after the Trump Administration’s classified briefings to lawmakers.

“I walk away from that briefing still under the belief that we have not obliterated the programme,” Senator Chris Murphy (Democrat-Connecticut) told reporters.

“The President was deliberately misleading the public when he said the programme was obliterated. It is certain that there is still significant capability, significant equipment that remain.

“You cannot bomb knowledge out of existence - no matter how many scientists you kill,” Murphy added.

“There are still people in Iran who know how to work centrifuges. And if they still have enriched uranium and they still have the ability to use centrifuges, then you’re not setting back the programme by years. You’re setting back the programme by months.”

Senator Lindsey Graham (Republican-South Carolina), a close ally of Trump, said “obliteration” was a “good word” to describe the strikes, which he said set back the programme for years. But he acknowledged Iran’s capabilities could be restored.

“The real question is, have we obliterated their desire to have a nuclear weapon?” Graham told reporters. “I don’t want people to think that the site wasn’t severely damaged or obliterated. It was. But having said that, I don’t want people to think the problem is over, because it’s not.”

A US official familiar with the Administration’s closed briefing for lawmakers said that Ratcliffe, the CIA director, highlighted the Israelis’ destruction of Iran’s air defences ahead of the US operation to assert that “the idea that they can easily rebuild anything is ludicrous”.

The director-general of the International Atomic Energy Agency, Rafael Mariano Grossi, offered a mixed assessment during an interview with CBS News that was broadcast today.

There is agreement that “a very serious level of damage” was done to Iran’s nuclear programme, he said.

“Iran used to have and still has, to some degree, capabilities in terms of treatment, conversion and enrichment of uranium.”

The facilities “have been destroyed to an important degree. Some is still standing,” he said.

Critics of Trump’s decision to use military force argue that he scuttled the chance of a diplomatic resolution, which is the only way of establishing an intrusive inspection regime to restrict and monitor Iran’s nuclear programme.

Tehran may also be more inclined to race towards a bomb as an insurance policy against any future regime change efforts by Washington or Israel.

Before the US attack, the US intelligence community concluded that Iran had not yet decided to build a nuclear bomb but was working on pathways to speed up the process if it chose to do so, US officials have said.

US officials counter that Trump’s strikes don’t preclude a diplomatic agreement and could improve the chances of one.

Last Wednesday, Trump announced that US and Iranian officials would meet this week to discuss a potential nuclear deal, but Iran’s Foreign Minister, Abbas Araghchi, quickly denied that any meeting would occur.

Araghchi has said the impacts of the US strike “were not little” and that Iranian authorities were determining the new realities of the country’s nuclear programme, which would inform Tehran’s diplomatic outlook.

Ayatollah Ali Khamenei, Iran’s Supreme Leader, has said Trump “exaggerated” the results of his strikes. “They attacked our nuclear facilities,” he said, “but they were unable to do anything important.”