MANILA, Philippines (AP) — The leader of the Philippines' largest Muslim rebel group says Islamic State-linked militants wanted his group to broker their possible withdrawal from Marawi city during the major military offensive against them but he refused to intervene.

Al Haj Murad Ebrahim of the Moro Islamic Liberation Front told The Associated Press in an interview late Tuesday that intervening would have been difficult because President Rodrigo Duterte has declared his government would not negotiate with terrorists.

Murad said the nearly two months of insurrection in Marawi is the worst he has seen in his more than four decades as a rebel in the country's south.

The militants in Marawi are now wracked by infighting and have expressed through religious emissaries they are ready to fight to the death.