A U.S. soldier was killed by a bomb blast on October 4 while on foot patrol during operations battling Islamic State (IS) militants in eastern Afghanistan, the U.S. military said.
Pentagon Press Secretary Peter Cook said no other U.S. personnel or Afghan troops were killed or wounded by the incident in Nangarhar Province, and the U.S. soldier was not specifically targeted.
A statement from U.S. Forces-Afghanistan said the soldier was killed while conducting operations alongside Afghan forces and the patrol triggered an improvised explosive device.
It said the mission was conducted as part of a larger United States-Afghan counterterrorism operation targeting Islamic State militants and members of the Al-Qaeda-linked Khorasan group.
Meanwhile, the IS on October 5 claimed responsibility for the blast in Nangarhar Province's Achin District near the border with Pakistan.
It claimed that three Afghan soldiers also were killed.
Nangarhar Province is a hotbed of IS activity. The soldier was killed in the province's Achin District near the border with Pakistan.
The Pentagon withheld the soldier's identity, pending notification of family members.
"Despite this tragic event, we remain committed to defeating the terrorists of the Islamic State, Khorasan Province, and helping our Afghan partners defend their nation," said General John Nicholson, who heads U.S. forces in Afghanistan.
About 2,300 US troops have been killed in Afghanistan since the U.S.-led invasion in 2001.