Iran may be able to restart its uranium enrichment in a "matter of months", according to Rafael Grossi, Director General of the United Nations' International Atomic Energy Agency.
"The capacities they have are there. They can have,... in a matter of months, I would say, a few cascades of centrifuges spinning and producing enriched uranium," Grossi said in an interview with CBS News on Saturday.
"But as I said, frankly speaking, one cannot claim that everything has disappeared and there is nothing there."
Meanwhile, US President Donald Trump said on Sunday that sanctions on Iran could be lifted if they agree to move forward in a peaceful manner.
"We have the sanctions. But if they do what they have to, if they can be peaceful and if they show us that they won't do any more damage, I would revoke them, and it would make a big difference," Trump told Fox News.
Trump explained that he turned down Iran's uranium enrichment request during negotiations, stating, "I wouldn't have let that happen", and then justified the bombing of Iran's nuclear plant by saying "Iran cannot have the nuclear weapon, and they were weeks away from having it".
On 22 June, the US launched multiple joint attacks with Israel against three of Iran's nuclear facilities: Fordow, Natanz and Isfahan. Trump had said the facilities were "totally obliterated" and the attacks had set Iran's nuclear programme back "by decades".
Extent of damage caused by strikes unclear
On 25 June, a leaked preliminary Pentagon assessment also found that Iran's nuclear programme has possibly only been set back by a few months. Following the outing of the report, Trump threatened to force journalists to reveal who leaked the report, which contradicted his narrative on Iran's bombing.
Meanwhile, in Iran, Ayatollah Ali Khamenei said the strikes had not achieved anything significant. However, Foreign Minister Abbas Araghchi stated "excessive and serious" damage has been done.
IAEA's Grossi has enquired to inspect the damaged facilities. However Tehran has rejected the request and on Wednesday voted to suspend its relationship with the IAEA, accusing it of siding with Israel and the US as it did not condemn the attacks on Iran.
But Grossi stays hopeful that the IAEA will be able to rebuild its relationship with Tehran.
"I have to sit down with Iran and look into this, because at the end of the day, this whole thing, after the military strikes, we will have to have a long-lasting solution, which cannot be but a diplomatic one," he said on Saturday.
In 2015, Iran and world powers reached a nuclear deal that barred Tehran from enriching uranium above 3.67% purity — the limit set for civilian nuclear use — and banned it from conducting enrichment at its Fordo plant until 2030.
Iran, which has always insisted its nuclear programme is peaceful, is a signatory of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and is required to submit to IAEA inspections.
But in 2018, Trump retracted the US from the deal, saying it failed to do enough to block Iran’s route to a nuclear weapon, and reinstated American sanctions.
By contrast, Israel is not part of the NPT, and while Tel Aviv has never said whether it possesses nuclear arms or not, according to the Stockholm International Peace Research Institute, the country is estimated to have at least 80 nuclear weapons.
Israel struck Iranian top military and nuclear targets on 13 June, claiming Iran was close to building a nuclear weapon.
Following a 12-day conflict, Iran and Israel have agreed to a ceasefire. However, Trump said he would "absolutely" consider bombing Iran again if intelligence found enough evidence that Iran's enrichment of uranium rose to worrying levels.
