The Philippines and the United States will begin war games near disputed South China Sea waters this week, showcasing fast-expanding military ties and likely further stoking tensions with China.
The annual exercises, which involve 2,300 marines from both sides and will last three weeks, will take place amid talks to further increase American military presence and deployment of its hard- ware in the former US colony.
They also come three weeks before US President Barack Obama is due to visit Manila, a huge moment for the Philippines as it looks for US support amid a worsening row with China over rival claims to parts of the South China Sea.
"The Chinese will view these military exercises as yet another example of the Philippines stirring up tensions in the South China Sea and of the US taking advantage of the situation to increase its military presence," said regional security expert Ian Storey.
Beijing, which insists it has sovereignty to nearly all of the South China Sea, has repeatedly railed at the Philippines for refusing to back down in the territorial dispute and seeking to draw the US closer.
Vietnam, Malaysia, Brunei and Taiwan also have competing claims to parts of the sea, believed to sit atop vast deposits of fossil fuels.
For the Philippines, the dispute will continue to be "the central driver" of efforts to intensify its alliance with the US, said Mr Storey, a senior fellow at the Institute of Southeast Asian Studies in Singapore.