WASHINGTON (CBSDC/AP) — A Princeton University professor warns that the Islamic State of Iraq and Syria could carry out a “mass slaughter in the United States.”

Speaking to The Glenn Beck Program, Robert George, a professor of jurisprudence, stated that ISIS terrorists will conduct these types of attacks if they are not stopped soon.

“They have every intention of getting here, and these are people who achieve what they set out to achieve,” George told the program. “Unless somebody stops them, they make good on their threats. They have threatened to carry out activity in the United States – killing people, mass slaughter in the United States.”

George states that these mass slaughters will happen unless the U.S. does something to stop the terror group.

“Our well-being, our security, our place in the world are vitally threatened by ISIS and ISIL. They will stop at nothing … in order to destroy anyone standing in their way so that they can establish the caliphate,” George explained.

The Princeton University professor believes now is the time to stop ISIS.

“We’re going to have to fight them eventually. Now do you want to do it now in Iraq or do you want to wait until they’re carrying out terrorist activity within the United States,” George said.

George also warns that the terror group won’t be afraid to use biological weapons on the masses.

“If they obtain biological or chemical weapons, they will use them. There’s no question. There’s nothing that’s stopping them from using those weapons,” George said, adding that he doesn’t know if ISIS has acquired these types of weapons yet.

Last week, Mike Morell, former deputy director of the CIA and current CBS News national security analyst, worried that ISIS could show up to the U.S. and conduct an immediate attack.

“The short-term concern is the Americans that have gone to fight with ISIS and the west Europeans that have gone to fight with ISIS could be trained and directed by ISIS to come to the United States to conduct small-scale attacks,” Morell told “CBS This Morning” last week. “If an ISIS member showed up at a mall in the United States tomorrow with an AK-47 and killed a number of Americans, I would not be surprised.”

Morell warned that over the long-term the extremist group could be planning for a 9/11-style attack that killed thousands of Americans.

“Over the long-term I worry that this group could present a 9/11-style threat. It took al Qaeda two-and-a-half years to plan 9/11. It would not surprise me to know that ISIS maybe thinking about going in that kind of direction,” Morell told CBS News.

President Barack Obama has authorized surveillance flights over Syria in an effort to monitor the terror group

CBS News reports that the Pentagon is drafting plans to use airstrikes against ISIS by both manned and unmanned aircraft in Syria to kill the terror group’s leaders and disrupt its operations.

Obama has yet to approve any airstrikes and Syrian Foreign Minister Walid al-Moallem said that they would need to be notified of any potential strikes or they would consider it a sign of “aggression.”

“Syria is ready to cooperate and coordinate with regional and international efforts to combat terror in accordance with U.N. resolutions and respect of sovereignty,” al-Moallem said Monday, according to CBS News.

He continued: “Everyone is welcome, including Britain and the United States, to take action against ISIS and Nusra with a prior full coordination with the Syrian government.”

Pentagon officials tell CBS News it’s unlikely they will notify President Bashar Assad’s government of any potential strikes.

Obama has only authorized airstrikes against ISIS in Iraq for humanitarian reasons and to protect American personnel in Erbil. But White House Press Secretary Josh Earnest stated that doesn’t mean the president will not pursue strikes in Syria.

“The president has already demonstrated a willingness, where necessary, to use military force to protect the American people, regardless of borders,” Earnest said.

Joint Chiefs of Staff chairman Gen. Martin Dempsey told reporters while traveling to Afghanistan that he will recommend the U.S. military move directly against ISIS in Syria once he determines the group poses a threat to the homeland.

“I can tell you with great clarity and certainty that if that threat existed inside of Syria that it would certainly be my strong recommendation that we would deal with it,” Dempsey said. “I have every confidence that the president of the United States would deal with it.”

ISIS has taken over a large swath of territory in Syria and Iraq, including Mosul. Last week, the terror group released a video showing the beheading of American journalist James Foley.

(TM and © Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)