The US-led coalition fighting the Islamic State group in Iraq and Syria swore in a new commanding general Tuesday, with the fight against the jihadists now in its fourth year.

Lieutenant General Paul Funk assumed command of the Operation Inherent Resolve joint task force at a ceremony on a military base in the region, officials said in a statement.

As part of a regular rotation, he took over from Lieutenant General Stephen Townsend, who had been deployed a year ago.

"The very existence of ISIS poses a threat to the civilized world and our way of life. We must defeat them, and our collective effort will defeat them," Funk said, according to the statement.

IS seized large parts of Iraq and Syria in 2014 as it sought to establish its self-declared "caliphate," but has faced a series of major defeats in recent months.

Forces backed by the coalition, which was founded in June 2014, have ousted the jihadists from Iraqi bastions such as Mosul and the extremists also have lost control of more than half of their de facto Syrian capital, Raqa.

Funk heads up the Army's III Corps, which had previously led the anti-IS coalition from September 2015 to August 2016.

Source: AFP