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House Speaker Nancy Pelosi, D-Calif., is calling on the Trump administration to immediately brief lawmakers on the U.S. airstrike that killed a top Iranian commander in Iraq and what the White House plans to do next.

The strike in Iraq was directed by President Donald Trump and killed Qassem Soleimani, the commander of Iran's secretive Quds Force, the Department of Defense announced Thursday night.

The move, which is likely to provoke retaliation from Iran, comes amid heightened tensions between the Trump administration and Tehran over rocket attacks aimed at coalition forces in Iraq. U.S. officials have said those attacks were likely carried out by Iranian-backed militias with links to the Quds Force.

"Tonight's airstrike risks provoking further dangerous escalation of violence. America — and the world — cannot afford to have tensions escalate to the point of no return," Pelosi said in a statement late Thursday.

The strike was carried out without an "authorization for use of military force" against Iran and without the consultation of Congress, the speaker said.

"The full Congress must be immediately briefed on this serious situation and on the next steps under consideration by the Administration, including the significant escalation of the deployment of additional troops to the region," Pelosi said.

Senate Minority Leader Chuck Schumer, D-N.Y., echoed Pelosi in remarks Friday on the Senate floor, saying that Trump will require congressional approval if he plans a large increase in troops to deal with potential hostility over a longer time.

"When the security of the nation is at stake, decisions must not be made in a vacuum," Schumer said. "The framers of the constitution gave war powers to the legislature and made the executive the commander-in-chief for the precise reason of forcing the two branches of government to consult with one another when it came to matters of war and of peace."

The Defense Department characterized the strike on Soleimani as "decisive defensive action to protect U.S. personnel abroad" and said in a statement that the Iranian commander "was actively developing plans to attack American diplomats and service members in Iraq and throughout the region."

Several Republicans, including Senate Majority Leader Mitch McConnell, R-Ky., House Minority Leader Kevin McCarthy, R-Calif., and Sen. Lindsey Graham, R-S.C., a member of the Senate Foreign Relations Committee, praised Trump's move.

"No man alive was more directly responsible for the deaths of more American service members than Qassem Soleimani," McConnell said Friday on the Senate floor just after the chamber gaveled in from its holiday break. McConnell added, "For too long, this evil man operated without constraint, and countless innocents have suffered for it."

The majority leader also said the administration planned to brief congressional staff Friday and would be giving a classified briefing to all senators early next week.

"Now, predictably enough in this political environment, the operation that led to Soleimani's death may prove controversial or divisive," McConnell said. "Although I anticipate and welcome a debate about America's interest in foreign policy in the Middle East, I recommend that all senators wait to review the facts and hear from the administration before passing much public judgment on this operation and its potential consequences."

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Graham said in a statement late Thursday that Soleimani "had American blood on his hands" and welcomed what he called Trump’s "bold action against Iranian aggression."

"To the Iranian government: If you want more, you will get more," Graham said.

Speaker of the House Nancy Pelosi said the airstrike that killed top Iranian general wasn't done with Congressional authorization. Saul Loeb / AFP - Getty Images file

Former national security adviser John Bolton, a longtime hawk on Iran, tweeted his "congratulations" to the Trump administration for the strike and said he hoped "this is the first step to regime change in Tehran."

Meanwhile, Ari Fleischer, who served as President George W. Bush's press secretary, said on Fox News that he hoped Soleimani's death would be cheered in the same way al Qaeda leader Osama Bin Laden's was.

Soleimani and the Quds Force were responsible for the deaths of hundreds of Americans and other coalition forces and orchestrated attacks on bases in Iraq within the last several months, including a Dec. 27 attack that killed a U.S. contractor and wounded several service members, the Defense Department said.

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Democrats were quick to condemn Soleimani on Friday but expressed concern about the consequences of his death and what they said was a lack of domestic oversight.

Rep. Adam Schiff, D-Calif., chairman of the House Intelligence Committee, tweeted that Soleimani "was responsible for unthinkable violence and world is better off without him."

"But Congress didn't authorize and American people don't want a war with Iran," Schiff said. "All steps must now be taken to protect our forces against the almost inevitable escalation and increased risk."

Ben Rhodes, former deputy national security adviser under President Barack Obama, questioned Trump's ability to handle the potential unknown consequences from the airstrike.

Does anyone think Donald Trump is equipped to handle a complex, enduring, international crisis that could play out in many countries and demand expertise, rigorous process, and judicious decision-making? — Ben Rhodes (@brhodes) January 3, 2020

Iran's Foreign Minister, Javad Zarif, called the U.S. strike an "act of international terrorism" and an assassination. He said in a tweet that it was an “extremely dangerous & a foolish escalation.”

"The US bears responsibility for all consequences of its rogue adventurism," Zarif said.

The US' act of international terrorism, targeting & assassinating General Soleimani—THE most effective force fighting Daesh (ISIS), Al Nusrah, Al Qaeda et al—is extremely dangerous & a foolish escalation.



The US bears responsibility for all consequences of its rogue adventurism. — Javad Zarif (@JZarif) January 3, 2020

In addition, at least two congressional Republicans called on the Trump administration to provide more details to Congress on its strategy for the region or any further steps.

Sen. Cory Gardner, R-Colo., in a statement commended the strike but said that the administration must be prepared for possible retaliation and should "consult closely with Congress on any next steps should the situation escalate."

Sen. Mitt Romney, R-Utah, also pushed for more information from the White House. "It's imperative that the US & our allies articulate & pursue a coherent strategy for protecting our security interests in the region. I will be pressing the Administration for additional details in the days ahead," he tweeted.

Qassem Soleimani was a depraved terrorist who had the blood of hundreds of American servicemen and women on his hands, and who was doubtlessly planning operations to further harm our citizens and allies. — Senator Mitt Romney (@SenatorRomney) January 3, 2020

Democratic presidential hopefuls raised concerns about the strike.

Former Vice President Joe Biden said that while "no American will mourn" Soleimani's death, killing him was a "huge escalatory move in an already dangerous region." He said in a statement that Trump had "tossed a stick of dynamite into a tinderbox."

Sen. Elizabeth Warren, D-Mass., said that although Soleimani "was a murderer, responsible for the deaths of thousands, including hundreds of Americans," the strike was a reckless move.

“Our priority must be to avoid another costly war,” Warren tweeted.

Sen. Bernie Sanders, I-Vt., tweeted that "Trump's dangerous escalation brings us closer to another disastrous war in the Middle East that could cost countless lives and trillions more dollars."

Sen. Cory Booker, D-N.J., tweeted Thursday night: "We have a president who has no strategic plan when it comes to Iran and has only made that region less stable and less safe."

Sen. Amy Klobuchar, D-Minn., said Soleimani "was responsible for directing Iran’s destabilizing actions in Iraq, Syria, and throughout the Middle East, including attacks against U.S. forces," but she also said the immediate focus is on protecting U.S. military and diplomatic personnel in Iraq and the region.

"The Administration needs to fully consult with Congress on its decision-making, response plans, and strategy for preventing a wider conflict," she tweeted.

In addition to Soleimani, the deputy of the militias known as the Popular Mobilization Units in Iraq, Abu Mahdi al-Muhandis, was also killed, according to Iraqi state television and the PMU.

He had been accused of plotting attacks on the United States since the 1980s. He was convicted in absentia and sentenced to death by Kuwait for his role in the 1983 attacks on the U.S. and French embassies in Kuwait, in which five Kuwaitis were killed.