House Intelligence Chairman Adam Schiff, D-Calif., responded late Thursday to the U.S. airstrike ordered by President Trump that killed Qassem Soleimani, the head of Iran's Revolutionary Guard, and six others at Baghdad’s international airport.

“Soleimani was responsible for unthinkable violence and world is better off without him,” Schiff tweeted hours after the strike.

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

Schiff’s statement was echoed by other Democrats, including House Speaker Nancy Pelosi, Sen. Chris Murphy, D-Conn., former Vice President Joe Biden, Sen. Ed Markey, D-Mass., and Democratic presidential candidate Andrew Yang.

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

She added that the strike was undertaken without consultation with Congress. "Congress must be immediately briefed on this serious situation and on the next steps under consideration by the Administration," she said.

TRUMP ORDERS ATTACK THAT KILLS IRANIAN GEN. QASSIM SOLEIMANI, OTHER MILITARY OFFICIALS IN BAGHDAD, PENTAGON SAYS

The Pentagon confirmed the attack Friday.

"At the direction of the President, the U.S. military has taken decisive defensive action to protect U.S. personnel abroad by killing Qasem Soleimani, the head of the Iranian Revolutionary Guard Corps-Quds Force, a U.S.-designated Foreign Terrorist Organization," the agency said in a statement.

The U.S. embassy in Baghdad was attacked earlier this week by protesters and Iran-backed militia. The embassy attack came after U.S. airstrikes killed 25 fighters of the Kataeb Hezbollah in Iraq, which is backed by Iran. The strikes were retaliation for the killing of an American contractor and the wounding of Iraqi service members during a rocket attack on an Iraqi military base.

It also escalates already heightened tensions in the region and between the U.S. and Iran over the last year.

Iran's Foreign Minister Javad Zarif tweeted after the attack "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."

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He added that the U.S. "bears responsibility for all consequences of its rogue adventurism."

Fox News' Frank Miles and Louis Casiano contributed to this report.