More than 200kg of uranium enriched to 60% are "missing," according to the journalist

Last month's US strikes on Iran's nuclear facilities failed to hit the country's stockpile of highly enriched uranium, Pulitzer Prize-winning journalist Seymour Hersh has claimed, citing US officials.

The attack, which involved seven US B-2 'Spirit' bombers carrying 30,000-pound bunker busters, was not even expected to "obliterate" the Iranian nuclear program, one of the journalist's sources admitted.

"The centrifuges may have survived and 400 pounds of 60% enriched uranium are missing," one of the officials said, adding that the US bombs "could not be assured to penetrate the centrifuge chamber . . . too deep."

The lack of radioactivity at the targeted Iranian nuclear sites - specifically Fordow and Isfahan - following the attack suggest that the enriched uranium stockpile had been moved ahead of time, one US official familiar with the matter said. Fordow, an underground complex built deep inside a mountain that many believed housed the stockpiles, was a particular focus of the attack.

The US officials cited by Hersh nevertheless believe that the location of the stockpile and its fate are "irrelevant" because of the serious damage the strike allegedly dealt to another Iranian nuclear site near the city of Isfahan.

The goal of the operation was to "prevent the Iranians from building a nuclear weapon in the near term - a year or so - with the hope they would not try again," a US official told Hersh. This could translate into "a couple of years of respite and uncertain future," the official added.

Following the strikes, US President Donald Trump claimed that the attack "completely and totally obliterated" Iran's nuclear program. CIA Director John Ratcliffe also told lawmakers that several key sites had been completely destroyed and would take years to rebuild.

However, intercepted communications suggested that Tehran had expected a worse impact from the strikes and that the real damage was limited, the Washington Post reported.

The strikes were part of a coordinated American-Israeli military campaign launched in mid-June. The Israel Defense Force bombed Iranian targets, claiming that Tehran was close to being able to build a nuclear weapon.

Hersh believes that Israel was the "immediate beneficiary" of the US strike. West Jerusalem does not officially acknowledge possessing nuclear weapons. The Jewish State may still have up to 90 nuclear warheads at its disposal, according to a recent report by the Stockholm International Peace Research Institute (SIPRI).