(Adds details of failed rescue, quote)
WASHINGTON, Aug 20 (Reuters) - The U.S. military earlier this year carried out an attempt to rescue journalist James Foley and other American hostages held in Syria, a U.S. official said on Wednesday, in an operation that the Pentagon said ultimately failed to find the captives.
The unsuccessful rescue operation "involved air and ground components and was focused on a particular captor network within ISIL," the Pentagon said in a statement, using a different name for the militant group. "Unfortunately, the mission was not successful because the hostages were not present at the targeted location."
President Barack Obama authorized the mission "earlier this summer," Lisa Monaco, Obama's top counterterrorism aide, said in a separate statement.
"The President authorized action at this time because it was the national security team's assessment that these hostages were in danger with each passing day in ISIL custody," she said.
Foley, 40, was executed by an Islamic State militant in a video that surfaced on the Internet on Tuesday. He was kidnapped in Syria in November 2012. In the video on Tuesday, Islamic State threatened to execute a second U.S. journalist in its custody, Steven Sotloff.
(Reporting by Jason Szep and Missy Ryan; Editing by Peter Cooney, Bernard Orr)