WASHINGTON — The Trump administration is weighing a range of options for a retaliatory action against Iran, including a cyberattack or physical strike on Iranian oil facilities or Revolutionary Guard assets, U.S. officials and others briefed on the deliberations told NBC News.

In a national security meeting on Monday, U.S. military leaders provided President Donald Trump with a menu of possible actions against Iran. But the president, seeking a narrowly focused response that wouldn't draw the U.S. into broader military conflict with Iran, asked for more options, people briefed on the meeting said.

That could entail a strike by Saudi Arabia, whose oil facilities were hit Sunday in an unprecedented attack, that the U.S. would support with intelligence, targeting information and surveillance capabilities — but without the U.S. actually firing any weapons at Iran, one person familiar with the planning said.

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Still, in the wake of Sunday's attack, U.S. military planners have revisited a long-identified list of potential Iranian targets that could constitute a proportional response. Those include a strike on Iran's Abadan oil refinery, one of the world's largest, or Kharg Island, Iran's biggest oil export facility. Attacks on either location would significantly impede Iran's ability to process and sell oil, which the Trump administration has already been working to restrict after pulling out of the Iran nuclear deal.

Other possibilities include hitting missile launch sites, bases or other assets belonging to the Islamic Revolutionary Guard Corps, the elite Iranian military unit blamed for much of Iran's paramilitary operations against adversaries outside of the country.

There were no indications that any U.S. military action was imminent, and officials said that no decision has been made. But the Defense Department is also working through options to increase its presence in the region by sending more forces and military assets to the Persian Gulf, officials familiar with the planning said.

Trump's desire for more options comes amid growing confidence by the U.S. intelligence community that Iran was behind Sunday's unprecedented attack on Saudi oil facilities. Some of that intelligence pointing to Iran as the culprit has now been made available to U.S. senators in a classified reading room, senators and their aides said Tuesday.

"I'm, like, 100 percent convinced," Senate Homeland Security Committee Chairman Ron Johnson, R-Wis., said after reading the intelligence report. He said the intelligence made available was about three pages long. "It's very brief, which means to me it's pretty cut and dry."

Although Trump has tweeted that the United States is "locked and loaded," both he and the Defense Department are deeply reluctant to get drawn into a military conflict with Iran. Those concerns have prompted a renewed look at non-military responses to Iran, such as a covert cyber action or increased sanctions that would be coordinated with other countries.

European governments have condemned the attacks but have stopped short of pinning the blame on Iran. A European official told NBC News it was highly likely that Iran was behind the attack, though governments were still studying intelligence reports. The Trump administration’s response to the attacks so far had created "confusion," and it was unclear if Trump still wanted to pursue talks with Tehran, the official said.

Bradley Bowman, a former Army officer and Senate national security aide, said the goal for U.S. military planners as they review longstanding options should be to re-establish the threat of deterrence without inflicting significant Iranian casualties, which could be exploited by Iran's government.

"Clearly those who conducted this attack were not deterred. That means inflicting pain," said Bowman, now a senior director at the hawkish think tank Foundation for Defense of Democracies. "But we want that pain to be inflicted in a wise way that does not increase the credibility in the eyes of the Iranian people of a regime that is not credible."

Any U.S. military action to retaliate for a strike against Saudi Arabia could also face resistance in Congress.

Lawmakers of both parties have repeatedly defied the president by pushing to limit U.S. military cooperation with the Saudis following the murder of journalist Jamal Khashoggi and the kingdom's bloody military intervention in Yemen. Yet the Trump administration has worked to maintain close ties to Saudi Arabia and its Crown Prince Mohammed bin Salman.

In a conference call Monday with House and Senate national security aides, Brian Hook, the top State Department official handling Iran policy, said that Saudi officials had impressed on the U.S. that they view the oil facility strikes as their equivalent to Sept. 11, according to an individual who participated in the call. The comparison raised eyebrows among congressional staffers, considering that there do not appear to have been any casualties in Sunday's strike, and that 15 of the 19 hijackers on 9/11 were Saudis.

"We don't have defense treaty with Saudi Arabia," said Sen. Chris Murphy, D-Conn. "We are under no obligation to defend Saudi Arabia and we have no interest in getting involved in an escalating regional conflict between those two countries."

Such skepticism about military action has also extended to Republicans. Sen. John Barrasso of Wyoming said he did not favor intervention "at this time," while Sen. Mitt Romney, a Utah Republican, said direct U.S. intervention would be "a grave mistake."

Trump, for his part, has suggested publicly he is not eager for war, and that he did not definitively blame the Iranians.

"It's looking that way," Trump said Monday of Iran's culpability. "That's being checked out right now."

Trump said the U.S. is prepared for war, but "with all that being said, we'd certainly like to avoid it," adding that he believes the Iranians "want to make a deal."

Complicating Trump's deliberations is the absence of a full-fledged national security adviser, whose role entails coordinating among the various national security agencies, following John Bolton's departure from the White House last week.

Trump has named deputy national security adviser Charles Kupperman as his acting national security adviser while promising to select a replacement soon. On Tuesday, Trump told reporters on Air Force One that he had settled on five potential candidates to replace Bolton.