The Philippines military has teamed up with Moro Islamic Liberation Front (MILF) fighters as it prepares for a final assault against the Maute armed group in the southern city of Marawi.

Soldiers were seen mingling freely with several hundred MILF fighters who have joined forces for an assault on fighters on the southern island of Mindanao.

The joint operation is the latest tactic by the Philippine government to try to stamp out fighters linked to the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group after months of battling a separate faction of fighters who have besieged the city of Marawi.

The alliance with MILF included "providing them with indirect fire support and even air support and other expertise," Major-General Arnel dela Vega told AFP, adding that the awkwardness of fighting alongside former long-time foes had evaporated.

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The Maute group, who have pledged allegiance to the ISIL group took control of Marawi in May. After a three-month siege, the fighters now control only a 500sq metre area.

More than 100 soldiers have died while almost 500 fighters have been killed, according to the Philippine military.

Thousands, including children, have been displaced due to the conflict and now live in host communities or 75 centres across Mindanao.

One man, who only identified himself as Ansari, told Al Jazeera that he refused an offer of $500 and an M16 rifle by the Maute to fight alongside them.

"They are evil. What they do is evil," he said.

"Look how they destroyed Marawi. I wouldn't be a part of them."

He said that many others who accepted the offer did so out of desperation, not ideology.

Vega said troop units would not merge with the MILF fighting groups because they had "different operational tactics and procedures" in the conflict.

"By and large the result has been substantially in our favour," he said.

Meanwhile, the United States has committed $14.3m in emergency relief and recovery assistance for communities affected by the ongoing conflict in Marawi and its surrounding areas.

US Ambassador to the Philippines Sung Kim announced the donation during a round table discussion with journalists at the US Embassy in Manila.

The aid is in the form of safe drinking water, hygiene kits, kitchen sets, shelter materials and 18 facilities with critical supplies and services to address tuberculosis and maternal, newborn and child health needs.