A prominent attorney is calling on lawmakers to pass legislation that would revoke the citizenship of any American who joins a terror group like ISIS or al Qaeda. 

Jay Sekulow, chief counsel at the American Center for Law and Justice, told Neil Cavuto that right now there is a "loophole."

He said the current law allows for citizenship to be revoked if an American joins a foreign state that is in conflict with the United States, but it doesn't apply to terror organizations.

Sekulow said the procedure to revoke citizenship should be "pro forma" once it's determined that an American has traveled to join ISIS. 

"There has to be due process under the Constitution. So there's a process under the existing Immigration and Naturalization Act that sets forth the revocation of citizenship procedure. The problem is, right now, joining ISIS doesn't qualify automatically for that status," Sekulow explained.

Sekulow, who wrote "Rise of ISIS," said the terror army wants to recruit American citizens through social media, bring them to Syria or Iraq, and then send them back into the U.S. 

Watch the interview above. 

On "Fox and Friends" Friday, we heard from Rep. Ted Poe (R-Texas) on the subject. He has introduced legislation to revoke the passports of Americans who join up with terrorists. 

"Many young males throughout the world leave their home country, including the United States. They go to Syria. They get radicalized and then they come back to their home country and commit crimes against the citizens of their own nation," said Poe.

"This legislation says the State Department can revoke a passport of any member of a foreign terrorist organization, like ISIS. It's a crime. It's a felony to be a member of a foreign terrorist organization. So when they go overseas, they're radicalized, they can't get back into the United States.  In fact, they can't use their American passport for any purpose. They show up at an airport in Europe, Paris, trying to come back to America. They can't get on the airplane and hopefully law enforcement will be there to detain them as well. We don't want those people back in the country; prevent them from traveling throughout the world." 

He was asked why this bill would not pass Congress easily. Poe said it was just recently filed, but expects it will be passed "soon." 

Poe said he "doesn't know" whether President Obama will sign the bill, but hopes that the president will see it as a "logical" step. 

Watch that discussion below.