ISIS Leader Urges World's Muslims to Join its Jihad

ISIS released a new audio message this weekend, issuing a call to arms to the world's 1.5 billion Muslims.

The voice is said to be the self-proclaimed leader of the terror group, Abu Bakr al-Baghdadi.

In the 24-minute audio clip, Baghdadi claims the U.S.-led alliance doesn't scare ISIS and mocked America for not putting boots on the ground. He says ISIS is thriving, despite setbacks this year.

"Be confident that God will grant victory to those who worship him, and hear the good news that our state is doing well. The more intense the war against it, the purer it becomes and the tougher it gets," he said.

Some of the recent setbacks include losing ground in Iraq and Syria, increased air strikes by the United State and its allies, and the loss of the group's second in command in August.

Still, Baghdadi said each trial only makes the group stronger.

He also threatened Israel and vowed to "liberate Palestine."

He also urged Muslims world over to join the fight, saying it is their Islamic duty to rise up everywhere.