U.S. forces have killed Abd ar-Rahman Mustafa al-Qaduli, an Islamic State finance minister also responsible for the terrorist group's external affairs, Secretary of Defense Ash Carter said Friday.
"We are systematically eliminating ISIL's Cabinet," Carter said, using an acronym for the terrorist group.
Carter would not say whether Qaduli, also known as Hajji Iman, was killed in Iraq or Syria, nor would he say whether the IS leader was killed in a raid or an airstrike.
WATCH: Defense Secretary Carter, Joint Chiefs Chairman Gen. Dunford
According to a U.S. defense official, Qaduli was "actively plotting to conduct terror attacks in the West."
The official said the U.S. military believes Qaduli was providing money to foreign fighters trying to develop and carry out attacks similar to the attack this week in Brussels.
This undated photo courtesy of the U.S. State Department's Rewards For Justice Program shows Abd ar-Rahman Mustafa al-Qaduli. The Islamic State group's second in command is said to have been killed in a U.S. raid in Syria.
Qaduli was released from Iraqi prison in early 2012 and had a $7 million reward on his head.
Others under attack
Carter also announced that Abu Sara, an Islamic State leader charged with paying fighters in Iraq, was targeted by U.S. forces this week.
A defense official told VOA that Sara was hit by a U.S. drone airstrike in Iraq.
Omar al-Shishani — also known as "Omar the Chechen" — was killed in a U.S. airstrike in March, and IS chemical weapons expert Abu Malik was killed by a strike in late January.
"Striking leadership is necessary, but it's far from sufficient," Carter said.
He added that the killing of Qaduli was consistent with U.S. strategy of pressuring the Islamic State in "every single way we can, from the leadership right down to supporting local forces on the ground."
"Momentum is in our favor," General Joe Dunford, the Chairman of the Joint Chiefs of Staff, told reporters at the briefing Friday, "but by no means would I say that we're about to break the back of ISIL or that the fight is over."
U.S. role questioned
The announcement of Qaduli's death comes one day after a senior U.S. official said Marines who were protecting U.S. forces near the northern town of Makhmur fired artillery rounds and illumination rounds to help Iraqi forces locate IS fighters.
Reporters questioned Carter and Dunford on whether these actions expanded the role of U.S. forces from purely supporting Iraqis to actively engaging in ground combat.
Dunford said he expected "increased capabilities provided to the Iraqis to set the conditions" to retake Mosul from Islamic State fighters, but he did not feel the actions in Makhmur constituted a change in the U.S. mission.
"This is not a fundamental shift in our approach to support the Iraqi forces," the top U.S. general said. "There's no inconsistency between what this artillery unit did and what our aviation support is doing every single day."
Also Friday, local media reported that Syrian soldiers had recaptured the city of Palmyra after fierce fighting with the Islamic State.
The group — in control of the strategically important area since May 2015 — had killed the local antiquities chief and blown up many historically significant sites in the area.
Katherine Gypson and VOA National Security Correspondent Jeff Seldin contributed to this report.