MANILA -

Japanese Prime Minister Shinzo Abe arrived Thursday for a two-day visit to Manila as the Philippines has boosted ties with China while taking a hostile stance toward Tokyo's main ally the United States.

The Philippines is Abe's first stop in a four-nation swing as the Japanese leader presses efforts to boost his country's trade and security engagements amid China's rise to Asian dominance. He will later travel to Australia, Indonesia and Vietnam.

Accompanied by his wife and a business delegation, Abe is the first head of state to visit since President Rodrigo Duterte took office in June. It's an important affirmation of Duterte's leadership at a time he faces domestic and international criticism for a brutal crackdown on illegal drugs that has claimed more than 6,000 lives.

"Japan is one of our strongest friends and ally and partner in this part of the world and we value this friendship," Duterte's foreign secretary, Perfecto Yasay Jr. said ahead of Abe's visit.

The two sides plan to sign agreements to bolster cooperation in agriculture, infrastructure and security. After Manila, Abe will travel to southern Davao city, Duterte's hometown where Yasay said the president may host breakfast for the Japanese premier at his home.

Japan may also provide help in the construction of rehabilitation centers for drug addicts, Yasay said.

China has backed Duterte's bloody crackdown on drug users and pushers, and a Chinese real estate magnate financed the construction of the biggest drug rehab center in the country, drawing praises from the president.

While Duterte has cozied up to China and Russia, he has railed at President Barack Obama's outgoing administration for raising alarm over human rights concerns. The brash-talking Duterte has repeatedly vowed to scale back joint military exercises and other defense engagements with the U.S., his country's treaty ally, but has walked back on many of his threats.

Duterte visited Japan in October when he and Abe agreed to cooperate in promoting regional peace and stability and acknowledged the importance of their alliances with Washington.

About two dozen activists led by four women who were forced into sexual slavery by Japanese troops in World War II protested outside the Japanese Embassy, calling for justice for their sufferings in a call that has largely been muted by the blossoming relations of the Asian neighbors.

Narcisa Claveria, 87, said she and other former sex slaves were treated "like pigs" by Japanese troops during the war, lamenting that many of her fellow victims had died without getting justice.

"Shinzo Abe, end the issue of women now," Claveria said at the protest. "You are meeting again with the president, will you bring forces of aggression here again? Are you going to make women here like pigs again?"

It's not clear if the demand by the former sex slaves would be raised by Duterte in his talk with Abe.

Japan is now among the top trading partners of the Philippines and one of its largest aid providers. It has also provided patrol ships to help the Philippines protect its territory amid longstanding territorial rifts with China.

Japan has expressed readiness to finance a major railway project in the south, where Duterte hails from, something that China also pledged.