After days of debate over how severely U.S. strikes had damaged three nuclear facilities in Iran, the fate of the country’s stockpile of enriched uranium remains a bigger mystery.

Over the years, as Iran built up its underground nuclear facilities and centrifuges, it amassed a large, 880-pound stockpile of uranium enriched to 60 percent, near bomb grade.

While U.S. intelligence agencies had assessed that Iran had not decided whether to make a bomb, they noted that Iran was only a few steps away from being able to turn its uranium into a weapon given the size of that stockpile.

There is little doubt that Iran’s entire nuclear program was substantially diminished by U.S. and Israeli strikes, and that it would struggle to quickly produce additional nuclear fuel.

But U.S. intelligence agencies had long assessed that, faced with the possibility of an attack on its nuclear facilities, Iran would try to move its stockpile of enriched uranium, either to keep as leverage in diplomatic negotiations or to use in a race to build a bomb.

In an interview on Sunday, Vice President JD Vance said U.S. officials wanted to talk to Iran about the stockpile. But on Thursday, the Trump administration pushed back on the idea that Iran had been able to move its enriched uranium before the U.S. strike.

President Trump suggested that the stockpile was destroyed or buried by the bombing of the site at Fordo. “Nothing was taken out of facility,” Mr. Trump posted on his social media site. “Would take too long, too dangerous, and very heavy and hard to move!”

And Karoline Leavitt, the White House press secretary, said that American intelligence agencies were watching the Iranian nuclear sites closely, “and there was no indication to the United States that any of that enriched uranium was moved prior to the strike.”

American officials say the intelligence collected so far on the stockpile is contradictory.

U.S. intelligence collected on Iranian officials shows they have different understandings of the stockpile’s fate, American officials said.

And parts of the nuclear facility at Natanz where some of the uranium was believed to be held were damaged, but not destroyed, by either the U.S. or Israeli attacks, officials said.

As a result, the intelligence community has not yet made a firm conclusion on how much the Iranians have retained, according to people briefed on the findings.

After a classified Senate briefing on Thursday, Republican lawmakers emphasized that destroying or seizing the stockpile was not part of the U.S. military mission. Senator Lindsey Graham, Republican of South Carolina, said the sites were severely damaged but that he “didn’t want people to think the problem is over, because it’s not.”

“I don’t know where the 900 pounds of enriched uranium exists, but it wasn't part of the target set for several years,” Mr. Graham told reporters. “They are obliterated today but they can reconstitute.”

There is confusion also about where the stockpile was originally. Mr. Trump has suggested it was at Fordo. Others have said some was at Natanz. The International Atomic Energy Agency has said the majority of the stockpile was at Isfahan, where Iran had reactors and other nuclear facilities that used the uranium. And some experts have suggested Iran has dispersed the stockpile.

The director general of the I.A.E.A said the Iranians told his inspectors that they planned to move the material if they thought it was under threat. It was stored in containers small enough, he said, to fit into “the trunk of an ordinary car.”

And in the days before the U.S. cruise missile attack on Isfahan, there was evidence of vehicles moving something into or out of those labs. I.A.E.A. officials say that since that stockpile of 60 percent enriched uranium was Iran’s most prized national possession, it would have been a breach of common sense to leave it all in one place.

Rafael Mariano Grossi, the I.A.E.A. director general, has held fast to his view that a good deal of that near-bomb-grade fuel remains in Iranian control. “I don’t know if they moved all of it,” he said this week. “But the evidence points to their moving out a lot of it.”

European officials said on Thursday that their preliminary assessments were also that Iran had moved the stockpile, though officials cautioned that those were early conclusions and that the exact location of the uranium was uncertain.

Other Western officials confirmed the assessment of top American intelligence officials on Wednesday that it could be years before those facilities are fully usable again. Crucially, the centrifuges at Fordo are unlikely to be operable, making it more difficult to purify its stockpile further, according to current and former officials.

In addition to damage to the centrifuges, Secretary of State Marco Rubio, speaking at the NATO summit in The Hague on Wednesday, said the destruction of the “conversion facility” in Isfahan had damaged Iran’s ability to move to a weapon. The facility converts enriched uranium gas into solid materials, and ultimately a metal that can be used to fabricate a nuclear bomb or a warhead.

But while Iran’s overall nuclear program, and ability to produce new fuel, has probably been set back significantly, how quickly the country could produce a bomb is another question.

In nearly two weeks of fighting, Israel killed a number of Iranian nuclear scientists. But if enough have survived, Iran could use a hidden stockpile to race toward a weapon. That would mean Iran’s ability to make a crude bomb was set back only months, even if its larger program suffered graver damage.

Representative Jim Himes of Connecticut, the top Democrat on the House Intelligence Committee, said the question of the stockpile was critical.

“Obliterating the sites means nothing if the Iranians moved enough 60% uranium, centrifuges and other weaponization tools to build a bomb at some possibly unknown location,” he wrote on social media. “The regime may be vile, but they are not stupid, and this stuff can be relatively easily relocated.

Jonathan Swan contributed reporting from Washington.