The U.S. killed a high-profile commander of Iran’s secretive Quds Force, the Department of Defense said late Thursday.

“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 department said in a statement.

Another man said to be the deputy of militias known as Popular Mobilization Forces was also killed in the strike that killed Suleimani — an iconic military commander of Iran’s military forces in Iraq, Syria, Lebanon and throughout the Middle East near Baghdad’s international airport, according to Iraqi Television reports.

In the past, the U.S. has credited Suleimani ‘s militias with combating an American enemy — ISIS in Iraq. Suleimani’s Quds Force was a division of Iraq’s Revolutionary Guard, widely believed to support a wide number of Iranian-backed terror groups such as Hezbollah.

“This strike was aimed at deterring future Iranian attack plans,” the Defense Department said in its statement. “The United States will continue to take all necessary action to protect our people and our interests wherever they are around the world.”

The Pentagon said that Suleimani was actively developing plans to attack American diplomats and service members in Iraq and throughout the region.

His death is likely to dramatically increase tensions between the U.S. and Iran, which were already heightened by the New Year’s attacks on the American Embassy in Baghdad.

Rioters for two days attempted to scale the fortress-like walls at the world’s largest embassy. They retreated under a show of force from the Pentagon; 100 Marines were airlifted into the compound and about 700 more Army paratroopers are expected soon in Kuwait from a global response force based at Fort Bragg in North Carolina.

Earlier, Defense Secretary Mark Esper threatened a pre-emptive strike against Iranian militia if there were any renewed attacks against U.S. personnel or interests in Iraq.

The Chairman of the Joint Chief told reporters attackers would run into a buzz saw.

Al-Muhandis was one of the closest Iraqis to Iran’s Islamic Revolutionary Guard Corps and he had been sanctioned by the U.S. Treasury for acts of violence against Americans. He had also considered to be a close advisor to Soleimani.

While details about the strike were not immediately clear, the reports come amid heightened tensions between the U.S. and Iran over rocket attacks in Iraq that U.S. officials had blamed on Iranian-backed forces and the attempted breach of the U.S. Embassy in Baghdad.

The conflict at the embassy occurred after U.S. fighter jets on struck weapons depots in Iraq and Syria that the United States said were linked with a group called Kataeb Hezbollah, which it blames for attacks on bases of the U.S.-led coalition fighting the Islamic State in recent months.

At least 25 militia fighters were killed in the airstrikes. The strikes followed the death of a U.S. contractor who was killed in a rocket attack on an Iraqi military base in Kirkuk that also hosted coalition forces Dec. 27. Several U.S. members were also injured.

Earlier this week, when asked about the possibility of war with Iran, President Donald Trump said that “I don’t see that happening.” “No, I don’t think Iran would want that to happen.”

“I want to have peace; I like peace. And Iran should want peace more than anybody,” Trump told reporters at his New Year’s Eve event at Mar-a-Lago in Florida.

At least one U.S. Congressman expressed alarm at the reports.

Sen. Chris Murphy, D-Connecticut, who sits on the Senate Committee on Foreign Relations, tweeted: “Soleimani was an enemy of the United States. That’s not a question.”

“The question is this — as reports suggest, did America just assassinate, without any congressional authorization, the second most powerful person in Iran, knowingly setting off a potential massive regional war? Murphy said in the tweet.

Sen. Marco Rubi, R-Florida, who also sits on the Foreign Relations Committee, tweeted that the U.S. and Trump “exercised admirable restraint while setting clear red lines and & the consequences for crossing them” following what he said were repeated attacks by the Islamic Revolutionary Guard Corps.

“#Iran’s Quds Force chose the path of escalation,” Rubio said in the tweet. “They are entirely to blame for bringing about the dangerous moment now before us.”

The Trump administration in April announced it was designating the Islamic Revolutionary Guard Corps as a foreign terrorist organization, which is the first time the U.S. had used that designation on part of another country’s government.

Since then there have been several tense incidents involving the U.S. and Iran, including when Iran in June shot down a U.S. surveillance drone that Iran’s Islamic Revolutionary Guard Corps said entered Iranian airspace. U.S. Central Command said the aircraft was in international airspace.

The Trump administration also blamed Iran for a September attack on oil sites in Saudi Arabia, which prompted the U.S. to deploy military forces to the Middle East that Esper said at the time would be defensive in nature.