MANILA/BEIJING (Reuters) - Philippines President Rodrigo Duterte travels to China next month on a visit that could redraw alliances in East Asia after his incendiary comments about the United States and active courting of Washington’s chief rivals.

FILE PHOTO - A Philippine flag flutters from BRP Sierra Madre, a dilapidated Philippine Navy ship that has been aground since 1999 and became a Philippine military detachment on the disputed Second Thomas Shoal, part of the Spratly Islands, in the South China Sea March 29, 2014. REUTERS/Erik De Castro/File Photo TPX IMAGES OF THE DAY

The friendly relationship between the Philippines and the United States has been one of the pillars of Washington’s strategic military rebalance to Asia under President Barack Obama. But the alliance has been under strain since Duterte came to power three months ago and chafed at U.S. criticism of his bloody war on drugs, which has led to the killing of more than 3,100 alleged drug users and dealers by police and vigilantes.

He has insulted Obama and then made it clear the Philippines will pursue a much more independent foreign policy than it has in the past.

That has included the Philippines extending an olive branch to China, despite the two countries being locked for years in a bitter territorial dispute in the South China Sea. Duterte has also spoken of reaching out to Russia.

“Ever since President Duterte took office, China and Philippines have been engaging in friendly interactions, which have yielded a series of positive results,” Zhao Jianhua, the Chinese ambassador to Manila, said at a Chinese National Day reception at the embassy this week.

“The clouds are fading away. The sun is rising over the horizon, and will shine beautifully on the new chapter of bilateral relations,” Zhao said.

Duterte plans to visit Beijing from Oct 19-21, and hold talks with both President Xi Jinping and Premier Li Keqiang.

Diplomatic and business sources in Manila have said he will be accompanied by about two dozen businessmen, which could lead to deals being forged that could underpin any improved bilateral ties.

But key to a successful visit will be an understanding of how to approach the dispute over the South China Sea. Beijing has angrily rejected a decision by an international court in July that ruled China’s claims to the waterway were invalid, after a case was brought by the Philippines.

Duterte wants China to abide by the ruling and allow access to the Scarborough Shoal, a traditional fishing ground for Chinese, Filipino and Vietnamese fishermen. But he has not insisted on the ruling being implemented and said he would like to negotiate on the row.

“Duterte giving us face means we have to rethink our policy,” a source with ties to China’s leadership and the military told Reuters. “We have to reciprocate his courtesy.”

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FISHING RIGHTS

Getting Filipino fishermen access to the Scarborough Shoal would be a major win for Duterte and add to his already sky-high domestic popularity. According to a recent survey, he has a record high approval rating of 92 percent even as he faces international opprobrium for the killings.

“When Duterte visits China next month, his agenda will focus on trade, investments and fishery cooperation with China, including access to Scarborough,” a Philippines foreign ministry official said, speaking on condition of anonymity.

Zha Daojiong, an international relations professor at China’s Peking University, said a deal over renewed Philippines access to Scarborough Shoal could be expected at the visit. But he said it would be a verbal rather than written agreement to avoid formally acknowledging the international court’s ruling, which upheld the historic fishing rights of both states.

“There’s many ways this meeting could be productive...even if there is likely to be some caution on both sides,” Zha said.

Officially, Beijing has yet to confirm Duterte’s visit, but the foreign ministry has said it welcomes a visit by him at an early date.

The Global Times, an influential tabloid published by the ruling Communist Party’s official People’s Daily, said in an editorial last week it could lead to a new chapter in ties.

“A new, positive interaction between China and the Philippines, starkly different from the Aquino era, may be unveiled,” it said, referring to the previous Philippines president, Benigno Aquino.

“Duterte shows stark differences from his predecessor in diplomacy and style. He seems to prefer more balanced diplomatic relations with other countries rather than being too reliant on the U.S.”

HITLER

Duterte has this month struck at the heart of ties with the United States by saying the two countries would not hold any joint naval patrols during his six-year tenure and calling for the withdrawal of U.S. special forces stationed in the restive south of the country. On Friday, he outraged Jewish groups by appearing to compare himself to Adolf Hitler, which could heap more pressure on Washington to publicly turn against him.

Despite the uncertainty, U.S. officials have maintained that all remains well.

“As it has been for decades, our alliance with the Philippines is ironclad,” Defense Secretary Ash Carter said on Thursday, speaking to American sailors aboard the U.S.S. Carl Vinson at its home port in San Diego.

But analysts think damage has already been done.

“Officials in Washington must now be seriously worried about the trajectory of U.S.-Philippine relations,” said Ian Storey, a South China Sea expert at Singapore’s ISEAS Yusof Ishak Institute.

“Especially military-to-military issues such as joint exercises and U.S. access to Philippine bases, and whether Duterte will try and cut a deal with Beijing over the South China Sea that will allow China to advance its maritime claims.”

But not everyone in China is rushing to embrace Duterte, because of his extreme unpredictability. Last month, despite the new-found bonhomie, the Philippines said at a summit of Asian nations in Laos that it was “gravely concerned” about Chinese boats preparing to build structures at the disputed Scarborough Shoal.

“We have to see what he actually does,” said Luo Liang, a researcher at the Chinese government-backed National Institute for South China Sea Studies in Hainan. “Although the signals from Duterte are good, we still need to wait and see.”