Philippine President Rodrigo Duterte has asked congress to extend martial law in the southern Mindanao region until the end of the year, to allow armed forces to quell the threat from the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group.

Duterte declared military rule over Mindanao, an island of 22 million people, for 60 days on May 23 when hundreds of ISIL-linked fighters occupied parts of Marawi city.

ISIL’s presence led to clashes that have killed more than 500 people.

But with scores of armed fighters holding out against government forces, Duterte met politicians late Monday and asked them to extend the law when it lapses on July 22, his spokesman Ernesto Abella said.

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“There is a looming situation in Mindanao which needs to be totally and completely addressed,” Abella said on Tuesday, adding that the primary objective of the extension was “to allow our forces to continue with their operation, unhampered by deadlines.”

The country’s constitution allows the president to impose martial law for up to 60 days.