President Donald Trump announced that he had ordered precision missile strikes on Syria in reaction to the use of chemical weapons by Bashar al-Assad.

“These are not the actions of a man. They are crimes of a monster instead,” Trump said, condemning the regime for using chemical weapons against his people in the ongoing civil war in the country. Early reports from Syria noted explosions on military sites as the president spoke.

The president made his remarks at the White House on Friday evening, arguing that preventing the spread of chemical weapons was in the interests of the United States. He pointed out that chemical weapons had been banned by civilized nations since World War I.

“The purpose of our actions tonight is to establish a strong deterrent against the production, spread and use of chemical weapons,” he wrote. “Establishing this deterrent is a vital interest of the United States.”

He described the Assad regime’s use of chemical as an “evil and despicable attack” that deserved a strong military response, despite signaling just days earlier his willingness to withdraw U.S. troops from the region.

But Trump specified that the United States was not acting alone, and confirmed that Britain and France were joining the military strikes.

“Today, the nations of Britain, France, and the United States of America have marshaled their righteous power against barbarism and brutality,” he said.

The president confirmed that these military attacks would be greater than last year, and would last longer than the limited strike he ordered in 2017.

“We are prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents,” he said.

Trump challenged Russia and Iran for supporting Assad in Syria.

“To Iran and to Russia, I ask, what kind of a nation wants to be associated with a mass murder of innocent men, women, and children?” he asked.

Trump specifically called out Russia for their support of Assad, urging them to stop backing the Syrian dictator in the Middle East.

“Russia must decide if it will continue down this dark path or if it will join with civilized nations as a force for stability and peace,” he said.

The president urged Americans to pray for members of the Armed Forces who were currently attacking military targets in Syria.

“Tonight, I ask all Americans to say a prayer for our noble warriors and our allies as they carry out their missions,” he said. “We pray that God will bring comfort to those suffering in Syria.”

The United States launched missiles on Syrian targets from warships on Friday and reports noted that B-1 bombers were making bombing runs in the area as well.

Briefing reporters after the strike, Secretary of Defense General James Mattis said he was “absolutely confident” that the Syria’s Bashar al-Assad was responsible for the recent chemical weapons attack.

“I am confident the Syrian regime conducted a chemical attack on innocent people in this last week, yes. Absolutely confident of it,” he said. “And we have the intelligence level of confidence that we needed to conduct the attack.”

Mattis described the military strikes as a “one time shot” and said that the future of attacks in Syria depended on Assad.

He said that the attack used “a little over double” the amount of weaponry used during President Trump’s 2017 missile strike against Syrian targets.

General Joseph Dunford concluded in the briefing that there were no American military losses in the attack despite Syria deploying surface-to-air missiles. The generals said that they were not aware of any immediate military reactions from Russia or Iran to the strikes.

Further details, the generals explained, would be revealed the following morning.