Airstrikes in Syria That Targeted Khorasan Group Disrupted Plots Against US, Gen. Dempsey Says

— -- The chairman of the Joint Chiefs of Staff said he believes that airstrikes in Syria that targeted the Khorasan Group succeeded in disrupting the group’s plots on U.S. and western targets.

In an exclusive interview with ABC News' Martha Raddatz, Gen. Martin Dempsey said, “I think it's absolutely safe to say disrupted. But the unknown is for how long.”

Dempsey added, “their aspiration to conduct attacks in Europe and the United States and elsewhere in the region remains an aspiration. I don't know how significantly they were disrupted.”

He said the group is still “capable of hitting the homeland because they have some skills, honed over the course of the last decade, and they are in collaboration with each other.”

Most of the 47 Navy Tomahawk missiles launched on the opening night of airstrikes in Syria targeted Khorasan Group targets around the northwestern Syrian city of Aleppo.

U.S. intelligence believes the group is made of about 50 al Qaeda veterans who moved from Afghanistan and Pakistan to western Syria to use the chaos of that country’s civil war to plan terror attacks in the west. They have been afforded protection by the Islamic rebel group Jubhat al-Nusra, which is affiliated with al Qaeda.

U.S. officials have said the group was in the final stages of executing a terror attack in either the United States or Europe that prompted heightened aviation security alerts this past summer. Officials said they believe that the group was planning to smuggle undetectable, non-metallic bombs onto Western passenger planes.

Dempsey said the U.S. is still trying to determine if the Khorasan Group’s leader, Muhsin al-Fadhli, a 33-year-old Kuwaiti was killed in the strikes. He said he is “hopeful” that is the case noting “he hasn't been very prominent on the airwaves, and so it remains to be seen.”

However, Dempsey said it appears that another unidentified senior leader may have been killed in the strikes.

“The assessment, which has been in open sources,” said Dempsey, “is that we got one for sure and possibly two. it takes a while to confirm.

The nation’s top military leader says the U.S. is maintaining “constant vigilance” on the group “they remain a threat, and as long as they are a threat, we will pursue them.”

See more of the interview with Gen. Dempsey on this Sunday’s broadcast of “This Week with George Stephanopoulos.”