Philippine President Rodrigo Duterte will travel to China this 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.

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.