The International Atomic Energy Agency said radiation data in the Gulf indicates there have been no "important radioactive release from any damaged nuclear power reactor" as a result of strikes on nuclear facilities in Iran.

Director General Rafael Grossi said the "worst nuclear safety scenario was ... avoided" in attacks, which the IAEA said "severely damaged several nuclear facilities in Iran."

"This month’s Israeli and U.S. strikes on Iranian nuclear sites would have caused localized radioactive releases inside the impacted facilities and localized toxic effects, but there has been no report of increased off-site radiation levels," the IAEA said in its release.

"From a nuclear safety perspective, Iran’s Bushehr Nuclear Power Plant and the Tehran Research Reactor represented our main concern as any strike affecting those facilities – including their off-site power lines – could have caused a radiological accident with potential consequences in Iran as well as beyond its borders in the case of the Bushehr plant," Grossi said. "It did not happen, and the worst nuclear safety scenario was thereby avoided."

President Donald Trump said on Friday he would bomb Iran again "without a question" if intelligence were to find that Iran can enrich uranium to a level higher than what he is comfortable with.

"Without a question. Absolutely," he told reporters in the White House briefing room.

"They're exhausted. The last thing they are thinking about is nuclear [weapons]," Trump said of Iran.

Responding to Ayatollah Ali Khamenei's claim that Iran won the war, Trump said, "You got beat to hell. Israel was beat up too, they were both beat up."

President Donald Trump on Friday doubled down on his claim that Iran's nuclear sites were "obliterated" and said it would take "years" before the country could restart its program.

"I don't believe that they're going to go back into nuclear anytime soon. They spent over $1 trillion on nuclear and they never got it together. And nothing was moved from the site, by the way, to do that is very dangerous. It's very, very heavy material," he told reporters in the White House briefing room on Friday.

Trump also said that Iran now wants to meet and negotiate a deal.

"I've been saying for 25 years, even as a civilian, you cannot let them have a nuclear weapon and that's what happened. It's been obliterated," he said. "It would be years before they could ever get going. And I really think it's probably the last thing they have to recover from a hell of a tough war."

Following a classified briefing, House Speaker Mike Johnson said that Iran’s nuclear capabilities suffered a "major setback" after the U.S. bombed three sites there last weekend, telling reporters that lawmakers received a "thorough" and "very helpful" closed-door briefing -- but Democrats left the briefing worried that Iran’s cache of enriched uranium may have not been destroyed.

Asked about that uranium stockpile by ABC News, Johnson downplayed the significance of an initial intelligence assessment from the Pentagon which showed that Iran’s stockpile was not destroyed.

"We have a sense about that, some of this is classified, but I will tell you that there was a CIA press release, I think it went out yesterday, and they concluded that this is a quote, 'Iran's nuclear program has been severely damaged,’ unquote,” Johnson said. “I'll put that in layman's terms. I would say it's a substantial setback."

But the only PhD nuclear physicist serving in Congress, Rep. Bill Foster, told reporters that he worries Iran’s uranium survived.

"I know this technology pretty well. I was very disappointed that we learned very little about the inventory of high enriched uranium, 60% enriched uranium, and its whereabouts and what that meant for the breakout time to Iran's first nuclear device," Foster said. "There is, I think frankly, a very over-optimistic portrayal of what was and was not accomplished by this mission, because we do not have understanding and control of where all of that material is."

Democrats said there are “massive inconsistencies” remaining -- and if the uranium was not destroyed, Foster believes Iran could still be "days" or "a very brief period of time" from building a nuclear bomb.

"We're talking about 20 or 30 scuba tanks full of material, where any two or so of those scuba tanks provide enough material for a first nuclear weapon," he said. "That is what we're trying to understand – where the location is and the disposition in the situation where the intelligence may or may not be complete."

Foster said "the game was lost" when President Trump withdrew from the Joint Comprehensive Plan of Action, also known as the Iran nuclear deal, in 2018.

"Under that under the JCPOA, we had very strict limits and enforced limits on their inventory of enriched uranium at different levels. And when that was lost, the game was lost," he said. "And now we're in a situation where they have very large inventories of quite significantly enriched uranium, and unfortunately that implies a very small breakout time to a first nuclear device."

Former Army Ranger Jason Crow of Colorado, leaving the briefing, said he was "shocked" by the "massive inconsistencies that remain between what Congress has been previously briefed and informed and what we heard today." The congressman added he is “not convinced whatsoever” that Iran’s nuclear sites have been completely destroyed.

-ABC News' John Parkinson and Lauren Peller