WASHINGTON — Lawmakers were sharply divided Tuesday over whether Iran poses an imminent threat to U.S. interests or the Trump administration is exaggerating intelligence to lay the groundwork for war.

Top administration officials briefed the House and Senate in two closed-door sessions for all members, presenting evidence that Iran may be poised to attack U.S. military and diplomatic personnel in the Middle East.

But some Democrats said that none of the information showed Iran was appreciably more of a threat now than in the past, and they accused the administration of being ready to attack at the slightest provocation.

U.S. and Western intelligence officials also have debated whether the intelligence, which includes photographs of Iranians loading missiles onto small boats, indicates that the nation is ready to strike or is responding defensively to economic pressure from Trump administration sanctions and a perception that the White House is eager for a fight.

Secretary of State Mike Pompeo, acting defense secretary Patrick Shanahan and the chairman of the Joint Chiefs of Staff, Gen. Joseph Dunford Jr., faced skeptical members, some of whom said they heard echoes of a previous administration’s case for war in the Middle East.

“I truly believe that the intel has been misinterpreted and misrepresented by Secretary Pompeo, by [national security adviser John] Bolton and other people that do want us to go to war in Iran, as a repeat to Iraq,” Rep. Ruben Gallego, D-Ariz., said upon leaving the briefing for House members.

“This is a case of somebody getting into somebody’s face and hoping that they’ll punch, and waiting to punch back,” said Rep. Joaquin Castro, D-Texas.

But some Republican lawmakers saw the information differently and pointed to “new,” “credible,” and “consistent” threats that Sen. Lindsey Graham, R-S.C., called “a game-changer.”

Graham said the administration’s recent actions, including the deployment of an aircraft carrier to the Persian Gulf, were in response to “strong intelligence” that Iran’s leaders had given Shiite militias in Iraq “more running room and direction that attacks against American interests and personnel were imminent.”

Republicans insisted that the administration was not hurtling toward a war with Iran, calling recent military moves “measured.” But Graham warned the administration not to shy from using force.

“If one American is injured or killed by actions coming from Iran, directly or indirectly, at the direction of the Iranian government, and you don’t respond, you will be up here explaining why you let those Americans get hurt and did nothing about it,” he said. “We’re pushing back against the regime and we’re resetting the rules of engagement. We’re letting them know that you’ve attacked us in the past . . . those days are over.”

Republicans and Democrats were directly at odds over whether the administration’s recent show of force is a potentially dangerous escalation, or legitimate deterrence.

“This is not an escalation,” Sen. Marco Rubio, R-Fla., insisted, arguing that the United States had “an affirmative responsibility to have military assets in the region prepared to defend” Americans deployed there, making the Trump administration’s moves “not an escalation. That’s a response.”

“Our recent actions over the last few weeks have been defensive,” Sen. John Neely Kennedy, R-La., said. He added that he thought the United States was “in a better posture today than two weeks ago,” but acknowledged that “we don’t know where it’s going to go next.”

Graham put the responsibility for de-escalation fully on Iran.

“The only way this changes is for Iran to change,” he said. “We’re not backing off, and if they use military force to try to stop our economic efforts to change their behavior, then they’ll suffer militarily.”

Pompeo, a longtime Iran hawk since his days representing Kansas in the House, said the officials described the administration’s “strategic campaign, the effort to push back against Iran’s malign activity, 40 years of terrorist activity” and “our efforts and our ultimate objective over the past days, which has been to deter Iran.”

Shanahan said he explained to members the “credible intelligence about threats to our interests in the Middle East and to American forces and how we acted on that credible intelligence.”

“Our biggest focus at this point is to prevent Iranian miscalculation,” Shanahan said. “We do not want the situation to escalate. This is about deterrence, not about war.”

Some Republicans pushed back against the assertion that President Trump’s advisers were hyping the intelligence.

“If anybody’s questioning that somehow there’s made-up in intelligence, that’s ludicrous,” said Rep. Adam Kinzinger, R-Ill.

Pompeo has also been trying to convince European allies that Iran poses a new threat. He traveled to Europe last week to meet with representatives from countries that continue to back the Iran nuclear deal that Trump withdrew from last year. But rather than convincing them of U.S. evidence, one European official said, he seemed most interested in the Europeans conveying to Iran how serious the United States was about responding to any attack.

Other countries have also become increasingly nervous. Iraqi Prime Minister Adel Abdul-Mahdi, who was visited by Pompeo earlier this month, said Tuesday that he was set to send delegations to both Washington and Tehran to help “halt tension,” according to media accounts in the region. Two days ago, a rocket of unknown origin landed in Baghdad’s Green Zone, where Iraqi government offices and the U.S. Embassy are located.

For Trump, the purpose of exerting “maximum pressure” on Iran through sanctions is “the belief that he will bring them around and they’ll realize they need to do a deal and the terms will be better,” said Dennis Ross, a former diplomat who negotiated Middle East agreements for Republican and Democratic administrations.

“The point is, he still thinks there’s a deal he can do. . . . I think for him, the real measure, in his mind, is showing he improved over what [President Barack] Obama did. My sense right now is the Iranians will try to outlast him,” Ross said, although “they may well have underestimated how much they will feel the pressure. There’s no question they’re hurting” from sanctions, “and they’re going to hurt more.”

In remarks Tuesday while visiting development projects in northwest Iran, President Hassan Rouhani acknowledged that his country was under pressure but said it would not “bow its head in the face of bullies,” Iran’s PressTV reported.

Lawmakers and administration officials also debated whether Trump has the authority to launch new military engagements in the Middle East under the nearly 20-year-old Authorization for Use of Military Force passed after the 9/11 attacks.

Shortly before the briefings, members of the House Appropriations Committee included a provision in the annual defense appropriations bill that would end the 2001 authorization, which gave the administration permission to pursue al-Qaida and its affiliates into Afghanistan. In the years since, the law has been used to justify campaigns against the Islamic State and other extremist groups. Lawmakers have never been able to agree across party lines on a replacement.

Rep. Barbara Lee, D-Calif., the author of the new provision, said it “absolutely” was part of the strategy to constrain the Trump administration’s options on Iran and was confident it would reach the floor for a vote.

Republicans seemed largely unconcerned with whether Congress would be consulted in advance of military action.

When asked whether officials would justify action under the president’s authority as commander in chief or under existing authorizations, Graham brushed off both suggestions, classifying any potential military action as falling under the “inherent right to defend yourself.”