Israel believes deeply buried stocks of enriched uranium at one Iranian nuclear facility hit by the US military are potentially retrievable, a senior Israeli official said. And the agency that built the US "bunker buster" bombs dropped on two other nuclear sites said on Thursday that it is still waiting for data to be able to determine if those munitions reached their targets.

Both developments widen the views on the damage from last month's strikes, when the US inserted itself in Israel's war in a bid to eliminate the threat of Iran developing a nuclear weapon. Iran says its programme is peaceful. 

President Donald Trump is adamant that the US strikes "obliterated" the three Iranian nuclear facilities it targeted. International assessments and an initial US intelligence assessment have been more measured, with the US Defense Intelligence Agency saying in a preliminary report that the strikes did significant damage to the Fordo, Natanz and Isfahan sites, but did not destroy them.

CIA Director John Ratcliffe has since told skeptical US lawmakers that American military strikes destroyed Iran's lone metal conversion facility, a setback to the nuclear programme that would take years to overcome, and that the intelligence community assessed that the vast majority of Iran's amassed enriched uranium likely remains buried under the rubble at Isfahan and Fordo. 

The White House didn't immediately respond to messages seeking comment on Thursday.

Much of Iran's enriched uranium is believed deeply buried at the third site, Isfahan, the senior Israeli official said. The US used B-2 stealth bombers to target the Fordo and Natanz sites. 

The official spoke to reporters on condition of anonymity to share Israeli assessments that had not been made public. Israel believes Iran's enriched uranium was distributed in the three sites and had not been moved, the Israeli official said. Nuclear and nonproliferation experts have warned that Iranians could have moved the stockpiles somewhere safer as Israeli strikes pounded Iran last month.