MANILA, Philippines (AP) — A Philippine communist rebel leader said Thursday that the insurgents can no longer hold peace talks with President Rodrigo Duterte's administration and that it is better to help oust him and negotiate with his successor.

Jose Maria Sison said Duterte wants the guerrillas to surrender without addressing the social ills that have inflamed one of Asia's longest communist rebellions. He criticized the president for being "subservient to U.S. imperialism" and blamed him for the "traitorous sellout" of disputed South China Sea territories to China.

After preliminary talks, both sides agreed to a new temporary cease-fire on June 21, with peace talks to resume on Thursday in Norway, which has been brokering the decades-long negotiations. But Duterte delayed the resumption indefinitely, antagonizing the guerrillas.

"Based on the implications drawn from the current impasse," the rebel front involved in the talks, the National Democratic Front of the Philippines, "can no longer negotiate with a government of the Republic of the Philippines that is headed by Duterte," Sison said.

"It is relatively easier and more productive for the National Democratic Front of the Philippines to participate in the oust-Duterte movement and to prepare for peace negotiations with the prospective administration that replaces the Duterte regime," said Sison, the founder of the Communist Party of the Philippines who has been in exile in the Dutch city of Utrecht for more than three decades. His comments were posted on the front's website.

Duterte shrugged off the threat and said he was ready to continue fighting the insurgents. The rural rebellion has raged for nearly half a century.

"If they're not willing to talk to me, that's fine. I have no problem so we continue with the war. Anyway, we've been there for 50 years, what if we add another 30 years?" Duterte told reporters when asked for a reaction.

The rebellion, which has raged since 1969, has left about 40,000 combatants and civilians dead and has stunted economic development in the impoverished countryside. The military says a few thousand Maoist insurgents are continuing to wage the insurgency.

When he took power in 2016, Duterte resumed peace talks with the guerrillas but canceled the negotiations last year to protest continued guerrilla attacks on troops, and signed an order declaring the rebel group a terrorist organization.

The rebels suspect Duterte delayed the talks' resumption to allow government forces to proceed with counterinsurgency attacks and to force the rebels to shift the venue of the talks from Europe to Manila, where Sison said the guerrillas could be subjected to surveillance and harassment. The volatile president has invited Sison to return home for the talks, assuring him of his safety.

Duterte has remained popular despite alarm over his bloody crackdown on illegal drugs and growing condemnation of his often expletive-laden speeches in the largely Roman Catholic country, including one last week in which he called God "stupid."

The largest protests against Duterte have been a fraction of the massive rallies that ousted dictator Ferdinand Marcos in 1986 and President Joseph Estrada in 2001.

"He stands isolated and ripe for ouster by the broad united front of patriotic and democratic forces," Sison said, but Duterte rejected that prospect.

"Which forces will join him? Let us see," Duterte said.