The U.S. Defense Department said Thursday it launched airstrikes across Iraq against the facilities of an Iranian-backed militia, a "direct response" for a rocket attack a day earlier that killed two Americans and a British service member.

The strikes were aimed at five weapon storage facilities, the Defense Department said, and meant to reduce capabilities for future attacks against coalition forces. They were conducted against Kataib Hezbollah facilities.

The attack on Wednesday targeted Camp Taji base, located 17 miles north of Baghdad, and also wounded 14 others.

Get Breaking News Delivered to Your Inbox

"These strikes were defensive, proportional, and in direct response to the threat posed by Iranian-backed Shia militia groups who continue to attack bases hosting [Operation Inherent Resolve] coalition forces," the Defense Department said in a statement.

"The United States will not tolerate attacks against our people, our interests, or our allies," Secretary of Defense Dr. Mark T. Esper added in the statement. "As we have demonstrated in recent months, we will take any action necessary to protect our forces in Iraq and the region."

Accoroidng to Agence France-Presse, Tehran later warned President Trump, saying in a statement from its foreign ministry that, "Instead of dangerous actions and baseless accusations, Mr. Trump should reconsider the presence and behavior of his troops in the area."

Tensions between the U.S. and Iran have been thrust into new territory in recent months, after a rocket attack on a base in Kirkuk, Iraq, killed an American contractor. The U.S. blamed the attack on Kataib Hezbollah, the same group that was targeted in this latest round of strikes, and retaliated with airstrikes that killed more than two dozen members of the militia.

Those strikes sparked protests at the U.S. embassy in Baghdad and thousands descended upon the compound. Days later, the U.S. killed Iranian General Qassem Soleimani, one of the most powerful figures in Iran, in an airstrike. Iran responded by launching a ballistic missile attack on American forces in Iraq.

There are at least 5,200 U.S. troops in Iraq. They're training and advising Iraqi forces as part of a global coalition.