Former Vice President and 2020 Democrat frontrunner Joe Biden on Thursday reacted to the assassination of top Iranian military commander Gen. Qassem Soleimani, accusing President Donald Trump of tossing a “stick of dynamite into a tinderbox.”

“No American will mourn Qassem Soleimani’s passing. He deserved to be brought to justice for his crimes against American troops and thousands of innocents throughout the region. He supported terror and sowed chaos,” Biden said. “None of that negates the fact that this is a hugely escalatory move in an already dangerous region.”

“The Administration’s statement says that its goal is to deter a future attack by Iran, but this action almost certainly will have the opposite effect,” the former vice president continued. “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 through the region and beyond. ”

“I’m not privy to the intelligence and much remains unknown, but Iran will surely respond. We could be on the brink of a major conflict across the Middle East. I hope the Administration has though through the second-and-third order consequences of the path they have chosen. But I feat this Administration has not demonstrated at any turn the discipline or long-term vision necessary — and the stakes could not be higher,” he concluded.

The Pentagon said Thursday that the U.S. military has killed Gen. Qassem Soleimani, the head of Iran’s elite Quds Force, at the direction of President Donald Trump.

An airstrike killed Soleimani, architect of Iran’s regional security apparatus, at Baghdad’s international airport Friday, Iranian state television and three Iraqi officials said, an attack that’s expected to draw severe Iranian retaliation against Israel and American interests.

The Defense Department said Soleimani “was actively developing plans to attack American diplomats and service members in Iraq and throughout the region.” It also accused Soleimani of approving the attacks on the U.S. Embassy in Baghdad earlier this week.

A statement released late Thursday by the Pentagon said the strike on Soleimani “was aimed at deterring future Iranian attack plans.”

The strike also killed Abu Mahdi al-Muhandis, deputy commander of Iran-backed militias in Iraq known as the Popular Mobilization Forces, or PMF, Iraqi officials said. The PMF media arm said the two were killed in an American airstrike that targeted their vehicle on the road to the airport.

Citing a Revolutionary Guard statement, Iranian state television said Soleimani was “martyred” in an attack by U.S. helicopters near the airport, without elaborating.

President Donald Trump, who was vacationing on his estate in Palm Beach, Florida, but sent out a tweet of an American flag.

Sen. Jim Risch (R-ID), chairman of the Senate Foreign Relations Committee, praised President Trump for ordering the strike.

“Congratulations to President Trump on his decisive action and the successful outcome. Qassem Suleimani was responsible for the deaths of hundreds of Americans and his death presents an opportunity for Iraq to determine its own future free from Iranian control. As I have previously warned the Iranian government, they should not mistake our reasonable restraint in response to their previous attacks as weakness,” Risch said.

“The U.S. will always vigorously defend our interests and allies in the face of terrorist conduct and provocations.“On behalf of every American serviceman and servicewoman who has either been killed or injured due to an Iranian-provided IED or rocket in Iraq over the years, today justice was done. Suleimani was responsible for the weapons program that caused those casualties and injuries with the use of those treacherous and cowardly devices,” the senator added.

The Associated Press contributed to this report.