US President Donald Trump said on Wednesday that the damage to Iranian nuclear sites from American missile strikes over the weekend was severe, even as he acknowledged that the available intelligence on the matter was inconclusive, Reuters reports.

His comments followed media reports on Tuesday revealing that the US Defense Intelligence Agency had assessed that the strikes had set back Iran's nuclear program by just a few months, despite administration officials saying the program had been obliterated.

"The intelligence was ... very inconclusive," Trump told reporters while meeting with NATO Secretary General Mark Rutte ahead of a summit in The Hague.

"The intelligence says, 'We don't know, it could have been very severe.' That's what the intelligence says. So I guess that's correct, but I think we can take the 'we don't know'. It was very severe. It was obliteration," Trump added.