Government and rebel negotiators have flown to the Netherlands for a resumption of the talks, which collapsed in February after Duterte angrily protested the killings of government troops in renewed attacks by the New People's Army rebels.
The formal opening ceremony of the Norwegian-brokered talks, which the government announced would take place yesterday, was delayed by a day.
He accused the guerrillas of undermining the talks and said the 48-year conflict, one of Asia's longest-running rebellions, may continue if the rebels don't accept his conditions.
Government chief negotiator Silvestre Bello III acknowledged the difficulty of the talks in a speech at the ceremony marking the resumption of talks. He welcomed the rebels' openness to a possible joint cease-fire.
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"Our discussion in the following days may prove to be difficult and exacting given the diversity of the positions taken by the parties on the issues at hand," he said in his speech, a copy of which was issued by the presidential palace in Manila.
"Without these, there will be no peace talks," Duterte said yesterday.
There was no immediate rebel reaction to Duterte's new conditions. In the past, they have rejected government conditions they deemed were a surrender of the advances they say they have made in their rural-based uprising.
"I'll really use those against the enemies of the government," he said. "I will not hesitate to use the full power of the state.