MANILA (2nd UPDATE) - President Rodrigo Duterte has issued an ultimatum to the Communist Party of the Philippines-New People's Army (CPP-NPA) to reciprocate his declaration of a unilateral ceasefire.

Duterte, who declared a unilateral ceasefire for CPP-NPA rebels during his first State of the Nation Address (SONA) Monday, said he is giving the communists until 5 p.m. on Saturday to reciprocate the truce.

Duterte said he will push through with offensive operations against the CPP-NPA if the rebel group won't reciprocate.

Duterte's statement came following an ambush of government troops by members of the CPP's armed wing, the New People's Army (NPA), in Davao del Norte.

One member of the Citizen Armed Force Geographical Unit (CAFGU) was killed and four others were wounded in the attack.

President Duterte talked to 3 wounded CAFGU after they were ambushed by the NPA last Wednesday. pic.twitter.com/eT3Ew8Faco

— Hernel Tocmo (@HernelTocmo) July 29, 2016

The squad leader of the group that was attacked said they were just returning to their detachment following Duterte's ceasefire declaration.

He said the troops were first hit by a landmine followed by gunfire from the rebels.

Duterte made the speech during a visit to the wake of the slain CAFGU in Kapalong, Davao del Norte Friday.

The government peace panel, headed by Silvestre Bello III, has sought an explanation about the ambush incident.

But Luis Jalandoni, chairperson of the National Democratic Front (NDF) peace negotiating panel, has asked for more time, saying it will take "a day or two" to really know what happened.

"What happened there in that exact incident, we have to find out and we stated that we cannot get it in such a short time of a few hours. We have to get the report from the side of the NPA in the area so that it will be an accurate check on what really happened," Jalandoni earlier told ANC.

READ: Reds seek more time to probe Davao del Norte attack

NDF peace panel negotiator Fidel Agcaoili also noted that the NPA has been on "active defense" since July 26, or a day after Duterte's SONA, while waiting for the operational details of the ceasefire declaration.

Duterte declared the unilateral ceasefire, stressing that war cannot be won by violence.

He added that he is trying to seek peace with everybody, except for criminals and the terrorist group Abu Sayyaf Group.

READ: Duterte warns CPP: Honor the truce or ceasefire is over

NPA command blames military

The NPA's Compostela Valley (ComVal) North Davao South Agusan Sub-regional Command, in a press statement Friday night, blamed the soldiers for getting waylaid in the ambush.

Aris Francisco, the NPA command's spokesperson, confirmed that communist rebels were behind the attack in Brgy. Gupitan, Kapalong on July 27.

He, however, claimed that the ambush "thwarted a military offensive" by the CAFGUs and Alamara paramilitary troops.

"The ambush was in adherence to the directive by the NPA National Operations Command for Red fighters to maintain on alert status and on active defense mode in response to Pres. Rodrigo Duterte’s declared unilateral ceasefire with the National Democratic Front, NPA and the Communist Party of the Philippines during his State of the Nation Address on July 25," Francisco said.

He disputed the AFP's account that the troops were only returning to their detachment in Sitio Patil, Barangay Gupitan.

"The AFP and the Alamara have been on active operation in Kapalong, resulting in several engagements including its July 5 ambush that wounded one Red fighter. Determined to continue its offensive military operations in Kapalong, the same troops ignored the ceasefire declaration of their Commander In Chief and again took off for combat operation from their detachment in Brgy. Patil on July 26," Francisco said.

"The NPA guerrillas were able to detect their movement enroute to what the military and the paramilitary purported to be fixed NPA targets some 20 kilometers away from their detachment. Had the Red fighters not taken the initiative to actively defend itself by intercepting the 72nd IB/Alamara troops, the operating AFP troops would have carried out its own combat action and inflicted damage against the NPA unit," he claimed. - with reports from Hernel Tocmo, ABS-CBN News