A preliminary classified U.S. report says the American bombing of three nuclear sites in Iran set back the country’s nuclear program by only a few months, according to officials familiar with the findings.

据几名知情官员透露，美国一份初步的机密报告显示，美国对伊朗三处核设施的轰炸仅使该国核计划进度倒退数月。

The strikes sealed off the entrances to two of the facilities but did not collapse their underground buildings, the officials said the early findings concluded.

这些官员表示，初步调查结果显示，打击行动封堵了其中两处设施的入口，但未摧毁其地下建筑。

Before the attack, U.S. intelligence agencies had said that if Iran tried to rush to making a bomb, it would take about three months. After the U.S. bombing run and days of attacks by the Israeli Air Force, the report by the Defense Intelligence Agency estimated that the program had been delayed, but by less than six months.

袭击前，美国情报机构曾表示，如果伊朗试图加速制造核弹，大约需要耗时三个月。在美国进行轰炸行动以及以色列空军进行数天打击之后，国防情报局的报告估计，该计划被推迟了，但延迟不到六个月。

The report also said that much of Iran’s stockpile of enriched uranium was moved before the strikes, which destroyed little of the nuclear material. Iran may have moved some of that to secret locations.

报告还称，伊朗在袭击前已经将大部分的浓缩铀转移，袭击摧毁的核原料极少。伊朗可能已将其中一部分原料转移到了秘密地点。

Some Israeli officials said they also believed that the Iranian government had maintained small covert enrichment facilities so it could continue its nuclear program in the event of an attack on the larger facilities.

一些以色列官员表示，他们也认为伊朗政府还保留着小型的秘密浓缩设施，以便在大型设施遭到攻击后还能继续推进核计划。

Other officials noted that the report found that the three nuclear sites — Fordo, Natanz and Isfahan — had suffered moderate to severe damage, with the facility at Natanz damaged the most. It is not clear whether the Iranians will try to rebuild the programs.

另有官员指出，该报告发现福尔多、纳坦兹和伊斯法罕这三处核设施遭受了中度到重度损坏，其中纳坦兹设施受损最严重。目前尚不清楚伊朗是否会尝试重建这些项目。

Former officials said that if Iran tried to quickly develop a bomb, it would be a relatively small and crude device. A miniaturized warhead would be far more difficult to produce, and the extent of damage to that more advanced research is not clear.

前官员表示，如果伊朗想迅速造出一枚核弹的话，那将是一个相对简陋的小装置。小型化弹头的技术难度要大得多，目前尚不清楚这种更先进的研究受到了多大程度的破坏。

Current and former military officials had cautioned before the strike that any effort to destroy the Fordo facility, which is buried more than 250 feet under a mountain, would probably require waves of airstrikes, with days or even weeks of pounding the same spots.

现任和前任军事官员在袭击前曾警告称，摧毁福尔多设施需要采用多轮打击，对同一地点进行连续数天甚至数周的轰炸，因为它深藏于山体下70多米的深处。

American warplanes did hit the same spots at least twice on Saturday. B-2s dropped 12 GBU-57 Massive Ordnance Penetrator bombs — often referred to as “bunker busters” — on Fordo, and six aboveground entry craters are now visible, according to Brian Carter, the Middle East portfolio manager at the American Enterprise Institute.

美军战机确于周六至少两次击中相同目标。据美国企业研究所中东项目主管布莱恩·卡特透露，B-2轰炸机向福尔多投下12枚GBU-57巨型钻地弹——常被称为“地堡克星”——现场可见六个地面入口弹坑。

But many military bomb experts believed that more than one day of strikes would be needed to complete the job.

但多名军事爆破专家认为，完成摧毁需多日的打击行动。

The initial damage assessment suggests that President Trump’s claim that Iran’s nuclear facilities were “obliterated” was overstated. Congress had been set to be briefed on the strike on Tuesday, and lawmakers were expected to ask about the findings, but the session was postponed. Senators are now set be briefed on Thursday, and House members on Friday.

初步毁伤评估表明，特朗普总统关于伊朗核设施遭“彻底摧毁”的说法言过其实。国会原定于周二听取关于此次袭击的简报，议员们预计会询问调查结果，但简报会因故推迟。参议院现定于周四听取简报，众议院则安排在周五。

Since the strikes, Mr. Trump has complained to advisers repeatedly about news reports that have questioned how much damage was done, said people with knowledge of the comments. He has also closely watched the public statements of other officials when they are asked about the damage to the nuclear facilities, they said.

据知情人士透露，空袭后，特朗普反复向顾问抱怨质疑打击效果的新闻报道。他们表示，总统还密切关注其他官员被问及伊朗核设施毁伤情况时的公开表态。

In a statement on Tuesday, Defense Secretary Pete Hegseth reiterated Mr. Trump’s early assessment.

周二，国防部长皮特·海格塞斯在一份声明中重申了特朗普早前的判断。

“Based on everything we have seen — and I’ve seen it all — our bombing campaign obliterated Iran’s ability to create nuclear weapons,” he said. “Our massive bombs hit exactly the right spot at each target and worked perfectly.”

“根据我们掌握的全部情报——我已经全部看过，轰炸行动彻底摧毁了伊朗制造核武的能力。我们的巨型炸弹精准命中每处目标点，效果完美。”

Officials cautioned that the five-page classified report was only an initial assessment, and that others would follow as more information was collected and as Iran examined the three sites. One official said that the reports people in the administration had been shown were “mixed” but that more assessments were yet to be done.

官员们强调，这份五页的机密报告仅仅是一份初步评估，随着更多信息的收集以及伊朗对这三处地点进行检查，后续还会有更新。一位官员表示，政府内部人士所看到的报告“结论不一”，不过更多评估仍在进行中。

But the Defense Intelligence Agency report indicates that the sites were not damaged as much as some administration officials had hoped, and that Iran retains control of almost all of its nuclear material, meaning if it decides to make a nuclear weapon it might still be able to do so relatively quickly.

但国防情报局的报告指出，这些地点受损程度未达部分政府官员预期，而且伊朗仍留有几乎所有的核材料，这意味着如果它决定制造核武器，仍然能够相对迅速地做到。

Officials interviewed for this article spoke on the condition of anonymity because the findings of the report remain classified.

因报告内容涉密，本文受访官员均要求匿名。

The White House took issue with the assessment. Karoline Leavitt, a White House spokeswoman, said its findings were “flat-out wrong.”

白宫对此评估提出异议。白宫发言人卡罗琳·莱维特表示，其结论“完全错误”。

“The leaking of this alleged assessment is a clear attempt to demean President Trump, and discredit the brave fighter pilots who conducted a perfectly executed mission to obliterate Iran’s nuclear program,” she said in a statement. “Everyone knows what happens when you drop 14 30,000-pound bombs perfectly on their targets: total obliteration.”

“泄露所谓评估报告显然意在贬低特朗普总统，诋毁执行完美任务摧毁伊朗核计划的英勇飞行员，”她在声明中说。“所有人都知道，当你将14枚3万磅炸弹精确投放到目标上时会发生什么：彻底摧毁。”

Elements of the intelligence report were reported earlier by CNN.

CNN此前已对这份情报报告的部分内容进行了报道。

The strikes badly damaged the electrical system at Fordo, officials said. It is not clear how long it will take Iran to gain access to the underground buildings, repair the electrical systems and reinstall equipment that was moved.

官员们表示，这些打击行动严重损坏了福尔多的电力系统。目前尚不清楚伊朗需要多长时间才能重新进入地下建筑、修复电力系统并重新安装已转移的设备。

Maxar Technologies公司提供的一张福尔多核设施的卫星图像。

There is no question that the bombing campaign “badly, badly damaged” the three sites, Mr. Carter said.

毫无疑问，这次轰炸行动“极其严重地损坏了”这三处设施，卡特说。

But initial Israeli damage assessments have also raised questions about the effectiveness of the strikes. Israeli defense officials said they had also collected evidence that the underground facilities at Fordo were not destroyed.

但以色列初步的评估结果，同样也对打击行动的效果提出了质疑。以国防官员表示，他们收集的证据表明，福尔多地下设施并未被摧毁。

Despite claims of the sites’ obliteration by Mr. Trump and Mr. Hegseth, Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, has been more careful in describing the attack’s effects.

尽管特朗普和海格塞斯声称这些地点被彻底摧毁，参谋长联席会议主席丹·凯恩将军在描述袭击效果时则相对谨慎。

“This operation was designed to severely degrade Iran’s nuclear weapons infrastructure,” General Caine said that at the Sunday news conference.

他在周日记者会上表示：“这次行动旨在严重破坏伊朗的核武器基础设施。”

The final battle damage assessment for the military operation against Iran, General Caine said on Sunday, standing next to Mr. Hegseth, was still to come. He said the initial assessment showed that all three sites “sustained severe damage and destruction.”

凯恩周日站在海格塞斯旁边表示，此次军事行动的毁伤效果尚未做出最终评估。他说，初步评估显示，所有三个地点均遭受“严重破坏和摧毁”。

General Caine added that it was “way too early” to assess how much of Iran’s nuclear program remained.

凯恩还表示，评估伊朗核计划保留下来多少还“为时过早”。

Gen. Joseph L. Votel, the former commander of Central Command, said in an interview, that he had “a lot of confidence in the weapons systems used.” But he added: “I’m not surprised that elements survived. That’s why you do battle damage assessments, because everything can go as planned but there are still other factors.”

前中央司令部司令约瑟夫·沃特尔将军受访时表示，他对“所用武器系统非常有信心。”不过，他也说：“有设施得以幸存也不意外。这正是为什么要开展评估的原因，即便一切按计划进行，仍存在其他变量因素。”

At a Senate hearing on Tuesday, Democrats also struck a more cautionary note.

在周二的参议院听证会上，民主党人也持更谨慎的态度。

“We still await final battle damage assessments,” said Senator Jack Reed of Rhode Island, the senior Democrat on the Armed Services Committee.

罗得岛州参议员、军事委员会的资深民主党人杰克·里德说：“我们仍在等待最终的评估。”

Representatives of the Defense Intelligence Agency did not respond to requests for comment.

国防情报局的代表未回应置评请求。