The United States piled new sanctions on Iran’s already crippled economy Friday and defended the killing of a top Iranian leader, saying he had been planning an “imminent” attack on US embassies.

The sanctions, announced at the White House, marked the latest salvo in a US-Iranian confrontation that risked sliding into war a week ago with the deadly US drone attack on general Qasem Soleimani, who was by some measures the second most influential person in Iran.

In response, Iran fired volleys of ballistic missiles at Iraqi bases housing US troops, without causing casualties.

While President Donald Trump said he would not respond further militarily, Washington is intent on maintaining pressure.

The sanctions mean “we will cut off billions of dollars of support to the Iranian regime,” Treasury Secretary Steven Mnuchin told reporters at the White House.

The measures targeting Iran’s steel industry and eight state officials came on top of massive sanctions already aimed at bringing the country’s economy to its knees.

US Secretary of State Mike Pompeo told reporters that sanctions so far “have deprived the regime of billions in revenue.”

“Oil revenues (are) down by 80 percent and Iran cannot access roughly 90 percent of its foreign policy reserves,” he said. “As long as Iran’s outlaw ways continue we will continue to impose sanctions.”

Among the senior Iranian officials targeted in the new measures were Ali Shamkhani, the secretary of Iran’s Supreme National Security Council, Mohammad Reza Ashtiani, the Iranian armed forces deputy chief of staff and Gholamreza Soleimani, the head of the Basij militia, a volunteer force loyal to the regime.

Seventeen Iranian metals producers and mining companies were listed.

The sanctions also included a network of three entities that are based in China and the Seychelles as well as a vessel “involved in the purchase, sale, and transfer of Iranian metals products,” the Treasury said in a statement.