Attempts by ISIS to carry out attacks in the United States are “inevitable,” CIA director John Brennan said in Sunday night’s 60 Minutes interview.

In an interview with Scott Pelley, CIA director John Brennan said that while the U.S. has the “technical capabilities” and the “human resources,” as a country we have to work harder to defeat the threat of an attack by the Islamic State on our soil, in addition to the threat of biological and cyber attacks.

While CIA operations would kick into full gear after an ISIS attack, preemptive actions have not been taken because the U.S. doesn’t want to “alienate others within that region and have any type of indiscriminate actions that are going to lead to deaths of additional civilians,” Brennan said.

After the November Paris attacks and the San Bernardino shooting in early December, the concern to better understand the threat that ISIS poses in the U.S. and the level of preparedness on the part of law enforcement and security became an increasingly growing topic of debate.

Brennan also confirmed that “ISIS has access to chemical precursors and munitions that they can use,” and have used on the battlefield, before adding that there is “potential” for ISIS to also export chemical weapons to the West.

A new report from the Organization for the Prohibition of Chemical Weapons (OPCW) indicates that ISIS used mustard gas against Kurdish forces in Iraq last year, according to Reuters.