Republican Sen. Mike Lee of Utah was furious on Wednesday after a Senate briefing on President Donald Trump's decision to order an airstrike that killed Iranian Maj. Gen. Qassem Soleimani.

Lee called it "probably the worst briefing, at least on a military issue, I've seen in nine years I've been here."

He said he "walked into that briefing undecided" on whether to support a war-powers resolution being pushed by Democratic Sen. Tim Kaine of Virginia. The resolution would limit the Trump administration's ability to take further military action against Iran without congressional authorization.

"That briefing is what changed my mind," Lee said. "I'm now going to support it."

Other lawmakers — both Republican and Democratic — also ripped the Trump administration after being briefed on the strike, saying they saw little evidence to support such drastic measures against Iran.

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Republican Sen. Mike Lee of Utah was furious on Wednesday after a Senate briefing on President Donald Trump's decision to order an airstrike that killed Iranian Maj. Gen. Qassem Soleimani, which brought tensions with Iran to a boiling point.

Lee told reporters that he "walked into that briefing undecided" on whether to support a war-powers resolution being pushed by Democratic Sen. Tim Kaine of Virginia. The resolution would limit the Trump administration's ability to take further military action against Iran without congressional authorization.

"That briefing is what changed my mind," Lee said. "I'm now going to support it."

He went on to call the briefing "probably the worst briefing, at least on a military issue, I've seen in nine years I've been here."

"Drive-by notification or after-the-fact lame briefings like the one we just received aren't adequate," he said.

"I find it insulting; I find it demeaning" to the Senate and the Constitution, the senator added. "It's un-American, it's unconstitutional, and it's wrong," he said after adding that the people who briefed senators on Trump's strike said the lawmakers could not debate the merits of the measure.

Republican Sen. Rand Paul of Kentucky, who stood alongside Lee as they addressed reporters, said he would also support a war-powers resolution to block further action against Iran.

"Today, this is Sen. Lee and I saying we are not abdicating our duty," Rand said.

Several other congressional lawmakers have voiced their dissatisfaction with the administration's briefings on the strike against Soleimani, who was Iran's most powerful military official and a widely revered figure within the nation.

Asked if she was convinced that there was evidence that Soleimani was planning an "imminent" attack on US personnel, as the administration has said, Democratic Sen. Elizabeth Warren of Massachusetts replied, "No" but said she could not elaborate further.

Democratic Rep. Pramila Jayapal echoed that, saying, "There was no raw evidence presented that this was an imminent threat."

On Tuesday, as questions swirled about how robust the intelligence supporting the Soleimani strike was, Defense Secretary Mark Esper was asked whether the Iranian attacks against US personnel were days or weeks away before Soleimani's death.

"I think it's more fair to say days, for sure," Esper said.

But reporting from The New York Times' Rukmini Callimachi indicated that the underlying intelligence for the strike was "razor thin."

Callimachi reported that one source told her there wasn't evidence of an "imminent" attack on US interests that could kill hundreds, as the White House has said. "The official describes the reading of the intelligence as an illogical leap," she reported.

In the days since the Soleimani strike, both Iran and the US ratcheted up their actions and rhetoric amid historically high tensions. Iran on Sunday withdrew from the Joint Comprehensive Plan of Action, and the US sent another 3,500 troops into Iraq after ordering Americans to evacuate the region in the wake of Soleimani's assassination.

Trump also ignited a firestorm when he tweeted on Saturday that he would target 52 Iranian cultural sites – which would constitute a war crime if carried out — if Iran retaliated for Soleimani's death. The president later walked back his comments and said he would "obey the law" with respect to military action.

On Tuesday, Iran retaliated against the US for the Soleimani strike by launching a missile attack on US and coalition forces in Iraq. However, Trump announced on Wednesday that the attack didn't result in any American casualties and said Iran "appears to be standing down."

Rather than retaliate with force, the US will impose tougher economic sanctions on Iran, Trump said, adding that the days of tolerating Iran's malign behavior "are over."