TEMPO.CO, Manila - Philippine President Rodrigo Duterte called off a 5-day-old cease-fire after communist guerrillas killed a government militiaman and failed to declare their own truce by a Saturday deadline, in an early setback to his efforts to end one of Asia's longest-raging rebellions.

It was the first irritant in what has been a blossoming relationship between Duterte, who calls himself a left-wing president, and the Maoist guerrillas, who have been waging a decades-long insurrection. Both sides had previously agreed to resume peace talks next month in Norway, and it was not immediately clear whether the talks would be affected.

Withdrawing his cease-fire order, Duterte said in a statement Saturday evening that he had ordered all government forces to go 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."

In a separate statement issued after the cease-fire order was lifted, the military said that the New People's Army guerrillas had "missed a golden opportunity" to demonstrate their commitment to peace.

"This could have been what the Filipino nation had been waiting for — the silencing of the guns that could have hastened development, especially in the countryside," military chief of staff Gen. Ricardo Visaya said in the statement, adding that the armed forces would abide by Duterte's latest order.

Duterte, who was sworn in on June 30, declared the government cease-fire Monday during his state of the nation address. Two days later, however, rebels killed the militiaman and wounded four others in southern Davao del Norte province, angering Duterte, who sought an explanation for the attack and gave the insurgents until 5 p.m. Saturday to declare their own cease-fire.

The rebels failed to declare a truce by the deadline. A regional rebel spokesman, Rigoberto Sanchez, instead accused the military of disobeying the president by continuing combat deployments and operations in the country's south.

"There is no conspicuous and veritable unilateral cease-fire exercised by" the military, police and paramilitary forces in the south," he said in a statement posted on a rebel website.

While the New People's Army in the south was ready to reciprocate Duterte's cease-fire, "it cannot be harangued to reciprocate a unilateral cease-fire order that is overtly mocked by the Armed Forces of the Philippines hierarchy and its ground troops and paramilitary forces," Sanchez said.

Sanchez said that government forces have continued to undertake combat operations, surveillance, reconnaissance, intelligence and psychological warfare in civilian communities, and alleged that troops were protecting "illegal activities such as drug trade and logging and mining pay-offs."

Military officials have denied rebel allegations that their combat operations were continuing, saying troops immediately shifted to defensive positions after the president announced the government cease-fire.

The militiamen had been recalled from a security mission following Duterte's truce declaration and were traveling back to their patrol base when they came under rebel attack, the military said.

Duterte flew to Davao del Norte on Friday to attend the slain militiaman's wake. Visibly upset, he asked the rebels if they would match his cease-fire.

"If I don't get the word from you, then I will lift the order of cease-fire," the president said, adding that he was rejecting rebel demands for him to withdraw government troops and policemen from certain rural areas.

Rebel leaders then asked Duterte to give them more time to study his truce declaration, and the president responded by saying that was "not a good response."

The decades-long communist insurgency has left about 150,000 combatants and civilians dead since it broke out in the late 1960s. It also has stunted economic development, especially in the countryside, where the Maoist insurgents are active.

Under Duterte's predecessor, Benigno Aquino III, peace talks stalled over the government's refusal to heed a rebel demand for the release of some captured guerrillas. Duterte, however, has agreed to the release of detained rebels, who would be involved in peace talks, and designated two allies of the guerrillas to Cabinet posts in concessions aimed at fostering the talks.

It was unclear whether the emerging differences between Duterte and the guerrillas would affect the peace talks, scheduled for Aug. 20-27 in the Norwegian capital of Oslo.

AP