The Trump administration’s effort to minimize dissent and hold back information about the president’s actions toward Iran has deepened tensions over the role of Congress in a military conflict.

Concerns about the lack of specifics shared with lawmakers continued to flare Thursday after a contentious classified briefing by President Trump’s national security team the day before, leading some GOP lawmakers to join Democrats in warning that the administration is failing to recognize the constitutional role Congress plays in decisions regarding the use of military force.

“Like everyone else in America, I’m worried about the separation of powers. This is like a bedrock thing. I could not have been more upset about that if they were insulting a member of my family,” Sen. Mike Lee (R-Utah) said Thursday a day after he angrily criticized top Trump administration officials following a briefing he characterized as insulting.

Lee, Sen. Rand Paul (R-Ky.) and Democratic senators said they were particularly upset by suggestions from administration officials that a congressional debate over the president’s power to take further action against Iran would be harmful to the morale of U.S. troops and said that they interpreted these ­remarks as an attempt to silence lawmakers. They were also angered over what they described as a refusal to answer any questions about when the administration must get congressional approval for military strikes.

“It was this attitude that we don’t have to tell Congress, we don’t have to include Congress,” said Sen. Tim Kaine (D-Va.). “They were being asked over and over again, ‘Okay, if you didn’t have to come to us to get authorization for the strike, what about this, what about that?’ They would make no commitment to ever come to Congress. And that was infuriating.”

The clash between the legislative and executive branches on military intervention abroad has only deepened since the Sept. 11, 2001, attacks, as Congress continuously ceded its war-making powers to successive presidents who have relied on congressional authorization nearly two decades old to justify military action abroad.

But the debate under Trump has taken on a fresh intensity. Despite the notable complaints from some key GOP lawmakers, most Republicans said they strongly back Trump’s moves against Iran and they have accused Democrats of sympathizing with terrorists due to their questioning of the administration’s decision to kill Iranian Maj. Gen. Qasem Soleimani in Baghdad last week.

Rep. Douglas A. Collins (R-Ga.) told Fox News on Wednesday that Democrats are “in love with terrorists, we see that, they mourn Soleimani more than they mourn our Gold Star families who are the ones who suffered under Soleimani” — comments that drew a rebuke Thursday from Iraq War veteran Sen. Tammy Duckworth (D-Ill.).

“I left literal parts of my body in Iraq, where I was fighting terrorists. Donald Trump spent months attacking an ­ACTUAL Gold Star Family,” she wrote on Twitter. “@RepDougCollins should be ashamed of himself for perpetuating this offensive lie.”

While Lee and Paul have been the most outspoken GOP critics of the administration’s handling of tensions with Iran, some other Republican lawmakers expressed unease with the lack of information they have been provided.

Sen. Todd C. Young (R-Ind.) said Thursday that there were “certainly infirmities” with the administration’s presentation to senators and said the legal analysis used to justify the strike that killed Soleimani “could’ve been more rigorous.”

“I understand — as a former Marine Corps intelligence officer — the real-world limitations to and the sensitivities associated with sharing certain information, even with members of Congress,” Young said. “But I left there feeling as though it would’ve been a lot more helpful had I gotten a little peek into some of the intel that informed the operational decisions.”

But top administration officials have suggested that some of the intelligence was too sensitive to disclose to members of Congress — a notion that has infuriated Democrats who say lawmakers have a right to know the underlying information that would guide their votes and actions on the weighty issue of war.

“The leadership in Congress and the House and Senate has seen this intelligence. And, frankly, the most compelling intelligence to support the fact that there was an imminent attack being developed by Qasem Soleimani is, frankly, too sensitive to share broadly,” Vice President Pence said in a Fox News interview Thursday. “It would compromise what we call sources and methods.”

The House passed legislation Thursday that would limit Trump’s ability to take military action against Iran without congressional approval. The vote was 224 to 194 with three Republicans joining Democrats in supporting the legislation. While the vote fell mostly along partisan lines, Trump stalwart Rep. Matt Gaetz (R-Fla.) voted for the resolution, warning his colleagues against the possibility of more “forever wars.”

“If our servicemembers have the courage to fight and die in these wars, as Congress we ought to have the courage to vote for or against them,” he said on the House floor.

The Senate is unlikely to pass the House resolution, but the fallout from Wednesday’s briefing continues.

The tensions during that session inside the classified facility in the basement of the Capitol began early in the question-and-answer portion, according to four senators and a senior administration official who were present for the 75-minute discussion, some of whom spoke on the condition of anonymity to describe the private briefing.

Senate Majority Leader Mitch McConnell (R-Ky.) asked Trump’s national security team whether a congressional debate about war powers and involvement in Iran could damage morale among the U.S. forces abroad.

In response, Defense Secretary Mark T. Esper signaled concern about any perception of disunity at a time when U.S. troops were engaged abroad, senators said.

“Esper responded and said — and I wish I had his exact words — basically said, ‘I think it would be unsettling to our troops and allies if it didn’t look like we were committed to this effort,’ ” recounted Sen. Richard J. Durbin (D-Ill.), who said he took issue with Esper’s view.

The Pentagon’s chief spokesman, Jonathan Hoffman, said Esper “indicated that he would be concerned about unintentional messages to the force that could result during an effort to repeal the 2002 AUMF at the same time that American troops are in harm’s way,” referring to the law that authorized the war in Iraq.

Hoffman said Esper emphasized that he was not questioning whether congressional debate over the use of military action was appropriate, “rather he stated a concern about how such a debate would be interpreted by the force.”

But inside the briefing, Esper’s explanations only emboldened Democrats eager to rebut the administration’s interpretation of its executive powers when it comes to military action.

After a handful of other senators asked questions, Durbin returned to the initial topic that McConnell raised and asked the administration officials whether they were saying Congress should not debate what he told them he believed it is required to debate under the Constitution for fear that it would be unsettling to our troops.

Later in the briefing, Sen. Christopher A. Coons (D-Del.) posed a hypothetical to the national security team: At what point would the Trump administration feel compelled to seek congressional authorization on military action toward Iran?

Secretary of State Mike Pompeo indicated that he would not entertain hypothetical scenarios, senators said, even after Coons posed the question three times. Coons insisted to the administration that his question was not a hypothetical, rather, a predictable turn of events that could emerge over the next six to nine months. Other senators in the room said this was a scenario that needed to be discussed.

As Pompeo responded, the normally mild-mannered Lee glanced over at the Democrats and threw up his hands in a gesture that signaled he was not satisfied with the administration’s answers, said Sen. Kevin Cramer (R-N.D.).

But Lee, Paul and Young — to a certain extent — appeared to be outliers among Senate Republicans.

Cramer, like many of his colleagues, said he was confident of the administration’s view that Soleimani posed an imminent threat to Americans, as well as its legal rationale to launch the strike that killed the Iranian military leader.

Senate Intelligence Committee Chairman Richard Burr (N.C.), a Republican member of the “Gang of Eight” that is privy to the most sensitive U.S. secrets, said in a brief interview that he did believe Soleimani was an imminent threat. Sen. Mitt ­Romney (R-Utah), the party’s 2012 presidential nominee, said the Trump administration gave a “largely effective presentation.”

“I don’t really understand,” Sen. John Cornyn (R-Tex.), a member of the Intelligence Committee, said of concerns from other Republicans. “Sounds like ships passing in the night.”

At the White House earlier Thursday, Trump played down the contentious portions of the Iran briefing, saying “numerous senators and numerous congressmen and women” telephoned him to say it was the “greatest presentation they’ve ever had.”

“Mike and Rand Paul disagreed because they want ­information that, honestly, I think is very hard to get,” Trump said. “It’s okay if the military wants to give it, but they didn’t want to give it. And it really had to do with sources and information that we had that really should remain at a very high level.”

Dan Lamothe, Josh Dawsey and Elise Viebeck contributed to this report.