Former House Speaker Newt Gingrich proposed the creation of a new version of the controversial House Un-American Activities Committee to root out American citizens who plan to commit terrorist attacks in the U.S.

“We originally created the House Un-American Activities Committee to go after Nazis. We passed several laws in 1938 and 1939 to go after Nazis and we made it illegal to help the Nazis. We’re going to presently have to go take the similar steps here,” Gingrich said in a Monday appearance on “Fox and Friends.”

Originally founded in 1938, the committee investigated suspected threats of Nazi subversion and anti-government propaganda. During the Cold War, its activities sprawled, leading to the blacklist of Hollywood stars and left-wing activists, writers, and academics accused of having Communist ties.

In 1959, former President Harry Truman infamously called the committee “the most un-American thing in the country today.”

Gingrich also suggested that the U.S. will inevitably “declare a war on Islamic supremacists” living here due to the number of terrorist attacks that have been committed by American citizens, such as those in San Bernardino, California and at the Fort Hood military base.

“We’re going to say, if you pledge allegiance to ISIS, you are a traitor and you have lost your citizenship,” Gingrich said.

Under current law, the U.S. cannot revoke the citizenship of natural-born U.S. citizens against their will.

Watch the video of Gingrich’s interview below courtesy of Media Matters.