US special forces are helping the Philippines military and police units to root out militants allied to Islamic State holed up in the southern town of Marawi, a US embassy spokesperson in Manila has said.

Until now there had been no confirmation US forces were assisting in the battle for Marawi City, now in its third week.

Their involvement comes after months of strain between the two allies stoked by Philippines President Rodrigo Duterte’s hostility towards Washington and his pledges to evict US troops, who have long provided training and assistance.

“At the request of the government of the Philippines, US special operations forces are assisting the AFP with ongoing operations in Marawi that helps AFP commanders on the ground in their fight against Maute and ASG militants,” the spokesperson said.

“For security reasons, we are not able to discuss specific technical details of U.S. support for ongoing operations.”

Clashes between government troops and the terrorists broke out on May 23, as state forces attempted to arrest terror leader Isnilon Hapilon, known to be the anointed ISIS chief in Southeast Asia.

President Rodrigo Duterte declared martial law on the entire island of Mindanao within hours of thefirst shots.

At least 200 have died in the firefights while more than 200,000 residents have fled the city since clashes started.

On Friday, the military said it hoped to liberate the city by June 12, Philippines Independence Day.
-with AAP