"Let me now announce that I am hereby ordering the immediate lifting of the unilateral ceasefire that I ordered on July 25 against the communist rebels," Duterte said in a statement released by the Presidential Communications Operations Office.
The decision to lift the ceasefire agreement comes after the NPA failed to fulfil the conditions of the ultimatum, put forward by Duterte, who demanded the leftist rebels to declare their armistice at 17:00 local time on Saturday (01:00 GMT).
The ultimatum comes in response to the rebels' attack on soldiers that occurred just two days after the announcement of unilateral ceasefire.
The Philippines government is mired in long-lasting standoff with the leftist rebels, which has lead to some 40,000 deaths. At the beginning of 2011, the conflicting sides tried to reach a ceasefire deal, but the initiative failed to succeed in February 2013.
