WASHINGTON — The Pentagon said Sunday that coalition forces had killed an extremist figure in Syria whom it identified as “the highest-ranking leader” in the Khorasan Group, a shadowy al-Qaida faction that U.S. officials have accused in the past of plotting attacks against the United States.

Abdul Mohsen Adballah Ibrahim al-Charekh, 30, a Saudi citizen more commonly known by his nom de guerre Sanafi al-Nasr, was killed Thursday in an airstrike in northwest Syria, Pentagon press secretary Peter Cook said.

U.S. counterterrorism officials have described the Khorasan Group as a small al-Qaida offshoot that took root in northern Syria two years ago. Although a fraction of the size of the Islamic State and other militant groups in the region, U.S. officials have said the Khorasan network is focused on planning strikes against Western targets and poses more of a direct threat to U.S. interests.

The Pentagon said that Nasr is the fifth Khorasan leader to have been killed by the U.S. military or its allies in the past four months. Khorasan is an archaic term used by some Islamist fighters to refer to a historical region covering parts of Afghanistan, Iran, Turkmenistan and other territory in central Asia.