Donald Trump and his top officials have pushed back on a leaked intelligence report that said US strikes on Iran only set its nuclear programme back by a few months.

Trump said at a Nato summit in The Hague on Wednesday that the strikes led to the "virtual obliteration" of Iran's nuclear capabilities and set its atomic programme back "by decades".

US Defence Secretary Pete Hegseth, who was also at the summit, said the preliminary Pentagon assessment was made with "low confidence" and the FBI was probing the leak.

On Tuesday, sources familiar with the initial report into Saturday's bombings told the BBC's US news partner CBS that Iran's stockpile of enriched uranium had not been eliminated.

They added that the strikes had only set the country's nuclear programme back by a few months - an assessment the White House swiftly described as "flat-out wrong".

The report said that strikes on the heavily fortified enrichment facilities at Fordo and Natanz had sealed off entrances but failed to destroy underground structures.

Officials familiar with the leaked Defense Intelligence Agency evaluation warned it was an early assessment that could change as more information became available.

The Defense Intelligence Agency is part of the Pentagon and specialises in military intelligence to support operations. It collects large amounts of technical intelligence, but is distinct from other agencies like the CIA.

The US has 18 intelligence agencies, which sometimes produce conflicting reports based on their mission and area of expertise. Different members of the US intelligence community disagree over the origins of Covid-19.

On Wednesday, while sitting alongside Nato Secretary General Mark Rutte, Trump initially acknowledged some uncertainty, saying the intelligence on the strikes was "very inconclusive".

But he then went on to say the attack "was very severe, it was [an] obliteration".

When asked if the US would strike Iran again should it resume nuclear activities, Trump said: "Sure, but I'm not going to have to worry about that. It's gone for years."

Trump later likened the strikes to America's atomic bombing of Hiroshima at the end of World War Two.

"I don't want to use an example of Hiroshima, I don't want to use an example of Nagasaki, but that was essentially the same thing - that ended a war," he said.

The US president was flanked by Secretary of State Marco Rubio and Secretary of Defence Pete Hegseth, who both echoed his scepticism about the leaked intelligence.

Hegseth said the leak was politically motivated and insisted the bombs landed "precisely where they were supposed to".

He added: "Any assessment that tells you it was something otherwise is speculating with other motives." He characterised the leak as "completely false".

Rubio also cast doubt on the leaked report's credibility, suggesting the contents had been distorted in the media and labelling the leakers as "professional stabbers".

The preliminary assessment also indicated that some of Iran's enriched uranium stockpile had been moved prior to the attack.

According to sources familiar with it, Iran's centrifuges remain largely "intact" with the destruction limited to aboveground buildings.

Entrances to two nuclear facilities were blocked and some infrastructure was damaged, they said, but much of the deeper installations survived the blasts.

In US intelligence terminology, "low confidence" typically indicates that the information is either poorly sourced, fragmented, or uncertain - making it less reliable than assessments graded with "moderate" or "high" confidence.

Hegseth's reference to the report being "low confidence" suggest it is tentative and its findings may change as more detail emerges.

The US struck three nuclear sites in Iran on Saturday - Fordo, Natanz, and Isfahan - using "bunker buster" bombs designed to penetrate hardened underground targets.

While the specific munitions used in the attack have not been confirmed, the 30,000lb (14,000kg) Massive Ordnance Penetrator (MOP), was thought to be the only weapon capable of destroying Iran's underground enrichment facilities.

Tehran has always maintained its nuclear programme was for peaceful purposes.

In the hours that followed Saturday's strikes, Gen Dan Caine, chairman of the joint chiefs of staff, told reporters that it would take time to assess the damage to the facilities, but added that "all three sites sustained extremely severe damage and destruction".

Satellite images showed six fresh craters clustered around two entry points at the Fordo nuclear sites, as well as grey dust and debris. However, it is unclear from these images how much damage was caused below the surface.

Hassan Abedini, the deputy political director of Iran's state broadcaster, said the three sites targeted by the US had been evacuated a "while ago", and that Iran "didn't suffer a major blow because the materials had already been taken out".

Both US and Israeli officials, meanwhile, have hailed the mission as a success. (BBC)