MANILA -- Three bells taken as war spoils by U.S. troops more than a century ago will be rung in a Philippine church on Saturday, in a move that symbolizes President Rodrigo Duterte's diplomatic pivot back to the U.S. amid concern over China's growing regional power.

Sung Kim, the U.S. ambassador to the Philippines, handed over the Balangiga bells in Manila this week, 107 years after an incident during the Philippine-American war from 1899 to 1902 that triggered a massacre.

On Sept. 28, 1901, locals in the central Philippine town of Balangiga on Samar Island rang the bells to signal a surprise attack that killed 48 U.S. troops. The following year, U.S. Brigadier General Jacob Smith directed his soldiers to reduce Samar into a "howling wilderness," his men killing every villager aged 10 or older, according to Filipino historian Rolando Borrinaga. While estimates vary, thousands were said to have been slaughtered.

Duterte used a speech at Congress last year to demand the return of the bells, calling them part of the country's heritage. His revival of the issue was partly an attempt to counter international criticism of his brutal war on drugs, which shook the Philippines' ties with its only military ally under previous President Barack Obama.

But President Donald Trump has largely sidestepped the human rights issues hounding Duterte, prompting him to dial down anti-U.S. rhetoric. Indeed, the two nations are quietly setting past differences aside as they grow increasingly wary of China's push for strategic and economic hegemony in the region.

After being chastised by Obama over his human rights record, Duterte in October 2016 announced a "separation" from Washington during a visit in Beijing to reboot ties with China. He also upgraded relations with Russia and downgraded military ties with the U.S.

The Roman Catholic church and belfry in Balangiga. The buildings were damaged by super typhoon Haiyan in 2013. © Reuters

Philippine Defense Secretary Delfin Lorenzana told a forum last week that Duterte had "changed his mind" and had allowed an agreement to boost military ties with the U.S. to proceed, paving the way for Washington to build military posts on Philippine soil.

"The U.S. is the biggest strength of the Philippines in dealing with China," Lorenzana said, in reference to his nation's dispute with Beijing over territorial claims in the South China Sea.

Assistance by U.S. troops in the liberation of Marawi City from Islamic State-aligned fighters last year became a critical juncture for improving ties, according to Gregory Poling, fellow with the Southeast Asia Program at the Center for Strategic and International Studies.

Duterte has called the U.S. "a best friend," and during the Association of Southeast Asian Nations summit in Manila in November last year, the Philippine president asked Trump to consider a bilateral free-trade agreement. In October this year, the two countries resolved some festering trade issues to move closer to formally starting talks.

American businesses that were initially spooked by Duterte's anti-West comments are showing signs of relief.

"Reassurances from senior administration officials have attenuated the impact of rhetoric against the U.S., as did the bilateral meeting during the 2017 ASEAN Summit," said John Forbes, senior adviser at the American Chamber of Commerce of the Philippines.

Philippine Foreign Affairs Secretary Teodoro Locsin last month hinted that the return of the bells may prompt Duterte to accept Trump's invitation to visit the U.S.

Even so, Duterte still has to balance ties with the world's two biggest powers as part of his "independent foreign policy."

During Chinese President Xi Jinping's state visit to Manila last month, the two leaders signed contracts and investment pledges worth billions of dollars, as well as a memorandum of understanding on oil and gas development.

But Duterte will put business aside this weekend, when he travels to Balangiga for the turnover ceremony that will put an end to the fractious issue between the Philippines and the U.S., its long-standing ally.

"The return of the bells was upon the demand of the Filipino people," Duterte said Thursday. "Nobody but nobody should ever claim success for that."