Duterte's request, which could be approved as early as next week, comes despite critics voicing concerns the move threatens human rights and places too much power in the leader's hands.

However, the president's spokesman Salvador Panelo said a third extension was needed in the southern region of Mindanao to "protect the nation and its people".

"A halt may only frustrate the progress we are witnessing in Mindanao and may even strengthen the rebellion and propel it to other parts of the country," Panelo said in a statement.

Martial law allows the military to establish control with measures like curfews, checkpoints and gun controls in a nation where civilians are allowed to own firearms.

It is a particularly sensitive matter in the Philippines because martial rule was used by dictator Ferdinand Marcos to remain in power during his two-decade reign, which ended in 1986 with a bloodless uprising.