Heval Agir, a US volunteer who joined Syrian Kurdish fighters to combat the Islamic State (ISIS), was killed in the operation to take the city of Manbij from ISIS militants.

The fighter, nicknamed Heval Agir, was a former marine in his mid-20s when he joined Kurdish forces of the People’s Protection Units (YPG) in northern Syria.

The US volunteer had appeared in an earlier video using a quote from the movie Starship Troopers.

“Let me tell you something. I’m from the United States of America and I say kill ’em all!” Heval Agir said on camera.

Hundreds of foreign fighters have joined the YPG and Kurdish Peshmerga forces to fight the ISIS.

The Kurds are very appreciative of the foreign fighters that leave their home countries to fight against the extremist group.

In June, the Kurdish administration of Rojava [Syrian Kurdish region] created a monument for foreign fighters fallen in the battle against ISIS in the city of Qamishli.

“ISIS jihadis said that the foreigners are unbelievers, but today we can see the people who go to the paradise, they are foreigners because they assisted humanity,” said Bave Shehid Mazlum (51), the father of a killed YPG fighter.