MANILA-- The Philippine government Sunday warned Islamist militants and their sympathizers to surrender or face the full force of the law.

Defense Secretary Delfin Lorenzana issued the warning a day after the Philippine Congress approved the extension of martial law in the entire Mindanao until the end of the year.

He said security forces are determined to defeat terrorism within the next five months when martial law is enforced in the south Mindanao region.

"With the overwhelming vote of confidence from our legislature and the ardent support of the Filipino people, your defense department will strive even more to deal with the rebellion decisively and expeditiously," Lorenzanna said in a statement.

Lorenzana urged militants to return to the government fold, saying the government is ready to welcome them anytime they want without any conditions.

"But if you persist in your crooked ways, the armed forces and the police will come after you without let-up," he said.

"The ones who should worry are the members of the terrorist-extremist group, the law violators, the supporters and sympathizers of the extremist-terrorist group and not the ordinary people."

Some 700 militants affiliated with Daesh overran Marawi City in the southern Philippines on May 23, prompting the government security forces to launch a series of airstrikes to crush the insurgents.

The ongoing battle has so far claimed the lives of some 600 people, including 105 soldiers and policemen and 428 terrorists and 45 civilians.

The government said 40 civilians, who fled the city when the war broke out on May 23, died from sickness in local hospitals.