Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)

A fighter of Libyan forces allied with the U.N.-backed government runs for cover during a battle with Islamic State fighters in Sirte, Libya, July 31, 2016. (Photo by Goran Tomasevic/Reuters)

Libyan forces allied with the U.N.-backed government fire a shell at Islamic State fighters' positions in Sirte, Libya August 15, 2016. (Photo by Ismail Zitouny/Reuters)

World War II enthusiasts take part in a re-enactament to mark the 70th anniversary of the Allied landings on Anzio beach, 52 km south of Rome, on January 25, 2014. (Photo by Andreas Solaro/AFP Photo)

Members of Libyan forces allied with the UN-backed government fire a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

Allie Labutis wears a painted “Merica” on her thigh during the fifth annual Made in America Music Festival in Philadelphia, Pennsylvania September 3, 2016. (Photo by Mark Makela/Reuters)

Fighters Feather “The Hammer” Hadden (L) and Allie “Babydoll” Parks compete during “Lingerie Fighting Championships 21: Naughty 'n Nice” at the Robinson Rancheria Resort & Casino on June 18, 2016 in Nice, California. Hadden won the bout. (Photo by Ethan Miller/Getty Images for LFC)

Ally Brooke, from left, Dinah-Jane Hansen, Camila Cabello, Lauren Jauregui and Normani Hamilton of Fifth Harmony, perform “Work From Home” at the Billboard Music Awards at the T-Mobile Arena on Sunday, May 22, 2016, in Las Vegas. (Photo by Chris Pizzello/Invision/AP Photo)