Jakarta. Indonesia, Malaysia and the Philippines will hold an informal meeting on the sidelines of the 31st Asean Summit in Manila on Sunday (12/11) to discuss the continuation of their joint plan of action to address increasing threats of terrorism in the region.

"The main purpose of this meeting is to discuss the situation in Marawi [in the southern Philippines]. There have been positive developments in the past few weeks and we expect the Philippines to share information on the progress and outcomes, and [the three countries] will discuss the next steps in the joint plan of action," Arrmanatha Nasir, a spokesman for the Indonesian Ministry of Foreign Affairs, said during a press briefing in Jakarta on Thursday.

The Philippine government wrapped up combat operations in Marawi City on Oct. 23, exactly five months after violent clashes between the country's security forces and Islamic militants resulted in the deaths of more than 1,100 people and drove hundreds of thousands from their homes.

The clashes raised concern in both Indonesia and Malaysia, who feared that militants could flee to nearby North Maluku and Sabah.

Indonesia initiated joint marine patrols with its two neighbors in the aftermath of the violence in Marawi to stem the movement of militants in the region.

Philippine security forces killed two high-profile figures in the Islamic State-affiliated Abu Sayyaf – Omar Maute and Isnilon Hapilon – during a series of actions in Marawi in October.

The trilateral meeting is a follow-up of a previous meeting in June, attended by the three countries' foreign ministers, defense ministers and police and intelligence chiefs.

The three countries previously agreed to cooperate in the joint development and implementation of counterterrorism measures and strategies to address the various aspects that underlie the threat of terrorism as part of an attempt to tackle the root causes. These include poverty, illegal drugs, crime and social inequality.

The three countries pledged to improve intelligence sharing, stop the flow of terrorist financing, weapons smuggling and movement, as well as contain the spread of terrorism-related content on the internet.

They also agreed to engage in efforts to promote deradicalization, rehabilitation and reintegration programs. This will be further discussed in the upcoming meeting.

"Our plan of action also considers future efforts to rebuild the affected areas when the situation in Marawi City returns to normal," Arrmanatha said.

Indonesian police captured several Islamic militants in several parts of the archipelago in October.