MANILA – President Rodrigo Duterte said he revoked a ceasefire with communist rebels after the insurgents failed to reciprocate his declaration at the end of a 24-hour deadline on Saturday.

Duterte had sought to bring the rebels back to the negotiating table in an effort to end one of the world’s longest-running Maoist insurgencies that has claimed 30,000 lives since the 1960s.

"Let me now announce that i am hereby ordering for the immediate lifting of the unilateral ceasefire that i ordered last July 25 against the communist rebels," Duterte said in a statement.

"I am ordering all security forces to be on high alert and continue to discharge their normal functions and mandate to neutralize all threats to national security, protect the citizenry , enforce the laws and maintain peace in the land,"

Formal talks were scheduled to begin in Oslo, Norway on August 20. It was not immediately known whether this would push through.

Duterte issued the ultimatum after a government militia man was killed and four others were wounded in what the military said was an ambush by the NPA in the southern province of Compostela Valley last Wednesday. The rebels owned up to the attack, but said they were thwarting an Army offensive.

The NPA, the armed wing of the Communist Party of the Philippines (CPP), is believed to have fewer than 4,000 gunmen at present, down from a peak of 26,000 in the 1980s, according to the military.

But it retains support among the poor in rural areas, and its forces regularly kill police or troops while extorting money from local businesses and politicians. -- with reports from Agence France-Presse