THE possible extension of President Rodrigo Duterte's declaration of martial rule in Mindanao would depend on the "parameters" laid by security officials, the Armed Forces of the Philippines (AFP) said Wednesday.

Speaking to Palace reporters, AFP spokesperson Brigadier General Restituto Padilla Jr. said security officials will assess if there is a need to extend the martial law in Mindanao in two weeks.

"We have set conditions that would specifically mention or act as a standard whether martial law should be extended or not," Padilla said.

"So these conditions are the parameters that will be used to say whether martial law should be extended or not. And that assessment regarding whether those conditions have been met has not yet been fully made. It will be made in about a week and a half or two," he added.

The 60-day martial law in Mindanao will expire on July 22.

Duterte's Proclamation 216 was questioned but the Supreme Court ruled Tuesday that it is legal.

On May 23, the Maute terror group, which allegedly pledged allegiance to Islamic State of Iraq and Syria (Isis), invaded Marawi City to convert it as the Southeast Asia fighters' territory.

Over 400 people have been killed in the lengthy battle in Marawi, consisting of 343 militants, 85 government troops, and 39 civilians.

The military no longer sets target date to retake Marawi City but aims to end the insurgency before the President delivers his second State of the Nation Address on July 24.

In case the state forces fail to liberate the conflict-torn city, Duterte can seek congressional approval to extend the imposition of martial law in the region.

Chief Presidential Legal Counsel Salvador Panelo, for his part, said the President may also issue another proclamation of martial law after the 60-day enforcement, only if "necessary."

"If Congress does not extend on the 60th day upon the initiative of the President, then, there can be no extension. Another proclamation is necessary," he said in a statement.

For now, Padilla said the government forces were "very glad" over the favorable decision of the high court that upheld the constitutionality of martial law. (SunStar Philippines)