The Vatican's ambassador to the United Nations has endorsed military action against the "Islamic State" (ISIS) terrorist group in Iraq and Syria, an unusual move because the Vatican traditionally has opposed force in the region, according to AFP.

In an interview with the US Catholic website Crux, Archbishop Silvano Tomasi said ISIS fighters were committing atrocities on a huge scale and the world needed to intervene. Tomasi said a coordinated and "well-thought-out coalition" was needed to do everything possible to achieve a political settlement without violence.

"But if that's not possible, then the use of force will be necessary," he added.