It calls itself the Khorasan Group, and U.S. officials say it was actively plotting to conduct an attack in the United States.
"The Khorasan Group is a group of extremists that is comprised of a number of individuals who we've been tracking for a long time," said Ben Rhodes, President Obama's deputy national security adviser. He said it includes former al Qaeda operatives from across the Middle East. "We believe that that attack plotting was imminent and that they had plans to conduct attacks external to Syria."
While the name is new, the Obama administration said it's made up of al-Qaida-linked fighters throughout the Middle East, including elements of al-Qaida in Iraq and the Nusra Front, the al-Qaida franchise in Syria.
One senior administration official described the group as many of the same people the government that has been tracking and that it is not a band of new terrorists.
A second official described them as experienced and dangerous, adding that the group has actively recruited Westerners.
Both officials were speaking on condition of anonymity because they were not authorized to speak publicly about the Khorasan Group.
The group is specifically responsible for the additional aviation security measures put in place in Western Europe and the United States in early July, the official said.
As recently as last week, White House and intelligence officials would not confirm that the group existed.
The first mention of it in the Western press came in a July 15 story by the Los Angeles Times, which described it as a ruthless arm of the Pakistani Taliban known for its use of beheading and torture to root out locals suspected of spying for the Americans. "These well-trained fighters often went barefoot, their faces covered with black cloth, with a black band around their heads that read, 'God is great'" the newspaper reported.
The Khorasan Group is separate from the Islamic State in Syria and Iraq — so much so that Obama on Tuesday sent two different notifications to Congress under the War Powers Resolution. One covered Khorasan; the other covered ISIL.
The name "Khorasan" refers to a region in Iran, but its members have come from Islamic countries from Pakistan to Yemen. They're in Syria, the officials said, precisely because ISIL-controlled territory provided a safe haven.
In fact, officials said, Khorasan posed such a threat that it's likely U.S. forces would have targeted the group in Syria even without the simultaneous attacks on ISIL.
"We have been very focused on this group and their exploitation of the safe haven and Syria," the second official said.