US lawmakers have reacted differently along party lines to the airstrike that killed top Iranian commander General Qasem Soleimani, the head of Quds Force.
The Quds Force is an elite unit of the Iranian Revolutionary Guards.
Iran vowed crushing revenge against the airstrike with warning from Iran's Supreme Leader Ayatollah Ali Khamenei that "severe revenge awaits the criminals" behind the attack, reported BBC.
The airstrike has raised concerns that Iran might retaliate with counter attacks triggering US President Donald Trump to encroach Congress' power to declare war, reports CBS News.
The airstrike revitalised a debate over presidential war powers as reported by The Washington Post.
Democrats expressed concerns about the legality and consequences of the attack, while Republicans praised the president for ordering the attack, reported CNN.
Republicans are positive about the strike as they regard Soleimani as a war criminal who is responsible for hundreds of American deaths, according to a report by The Washington Post.
However, Democrats vented over that the escalation of existing hostile relation with Iran. They considered the action a dangerous step toward war. They also complained that Trump ordered the action without congressional input, The Washington Post report said.
"The attack might lead to further dangerous escalation of violence," warned Nancy Pelosi, house speaker in the US Congress, adding "This action was taken without the full consultation of Congress," a CBS News article said.
One of the Trump allies, Sen Lindsey O Graham praised the president by calling the strike a "blow to [an] Iranian regime that has American blood on its hands," reported The Washington Post.
Another Trump supporter, McCarthy - a House Minority leader - appreciated the killing as a "statement to those seeking to attack America."
He said that the president responded appropriately to violence by Iranian-backed groups in Iraq, including an attempt to storm the US Embassy in Baghdad.
Meanwhile, some of the US lawmakers supported the attack and expressed concerns about consequence at the same time.
House Foreign Affairs Committee Chairman Eliot L Engel echoed Pelosi, saying, "The strike went forward with no notification or consultation with Congress. To push ahead with an action of this gravity without involving Congress raises serious legal problems and is an affront to Congress's powers as a coequal branch of government.
"Even if this strike was in self-defense, no current congressional authorization covered it and the President needs to notify Congress within 48 hours pursuant to the War Powers Resolution. The law requires notification so the president can't plunge the United States into ill-considered wars."
While, Democratic former Vice President Joe Biden, who is vying for the upcoming presidential election, said "no American will mourn" Soleimani but that the strike that killed him is a "hugely escalatory move."
A CNN report quoting a Biden statement said, "President Trump just tossed a stick of dynamite into a tinderbox, and he owes the American people an explanation of the strategy and plan to keep safe our troops and embassy personnel, our people and our interests, both here at home and abroad, and our partners throughout the region and beyond."