In a bold vow to hunt down one of the most wanted men on the planet, the spokesman for U.S. forces in Iraq told the Islamic State terror group's chief Abu Bakr al-Baghdadi his days as a free man were numbered.

“I hope that al-Baghdadi watches these press conferences because I want him to know that we are hunting him and we will find him just like we found his mentor Zarqawi and killed him. Just like we found the grand master of terrorism Usama bin Laden, we killed him," Col. Steve Warren told reporters.

"We are going to find Baghdadi, and he will taste justice. I don’t know if that justice will look like a hellfire missile or if it will look like a dark prison cell somewhere but he will find justice one day."

A U.S. airstrike in Iraq killed Abu Musab al-Zarqawi in 2006, five years before a U.S. raid killed Usama Bin Laden in Pakistan. Analysts say Zarqawi led the Al Qaeda faction that would ultimately become known as ISIS.

Warren says he believes Baghdadi is alive and continues to move between Iraq and Syria. “This is a terrorist that should not sleep well ever,” Warren added.

A long awaited program to train “dozens” of Syrian fighters has also started, following the Pentagon's failed “train and equip” program last fall. Gen. Lloyd Austin, commander of U.S. Central Command, told Capitol Hill lawmakers in September that only “four or five” U.S. military-trained fighters remained in the battle against ISIS in Syria.

Fox News' Lucas Tomlinson and The Associated Press contributed to this report.