About 200 Muslim rebels arrived in the Philippine capital Manila today for the signing of a preliminary peace pact.
The Moro Islamic Liberation Front's decades-long rebellion has cost the lives of tens of thousands of people and held back progress in the south, where Muslims make up a sizeable minority.
Government and rebel negotiators forged the framework peace agreement in Malaysia after 15 years of negotiations.
The pact's signing on Tuesday will be witnessed by President Benigno Aquino, Malaysian Prime Minister Najib Razak and rebel chairman Al Haj Murad Ebrahim.
About 300 Muslims from Manila and southern provinces held a noisy rally outside the palace in support of the preliminary accord today.
They called for more development in the resource-rich but impoverished southern Mindanao region, the homeland of minority Muslims in the predominantly Roman Catholic nation.
Security has been tightened in the capital, although no disruptions were expected.
The agreement is to be signed by government negotiator Marvic Leonen and his rebel counterpart Mohagher Iqbal, and will serve as a roadmap outlining general agreements on major issues, including the extent of power, revenues and territory of a new Muslim autonomous region to be called Bangsamoro.
The two sides are to negotiate details to achieve a final peace deal by 2016, when President Aquino's six-year term ends.
The preliminary accord also establishes a 15-member Transition Commission that is to draft a law creating the new Muslim-administered region.
Rebel forces will be deactivated gradually, the agreement says, without specifying a timetable.