The Philippines and the United States will launch naval exercises on Tuesday close to the South China Sea, which is the focus of a simmering regional territorial row.
The longtime allies have emphasised the event is an annual one aimed at deepening defence ties, and not linked to rising concern in Manila about allegedly aggressive Chinese actions in the much coveted seas.
"The US and Philippine navies have a long history of working together, and exercises like (these) provide a great venue for us to hone our skills," said the US commander for the 11-day exercises, Captain David Welch.
Nevertheless the exercises are being seen in Manila as a timely show of unity between the Philippines and its former colonial ruler.
Two state-of-the-art US missile destroyers, along with the host's World War II-era warships, will patrol the Philippine waters of the Sulu Sea.
The Sulu Sea is separated from the South China Sea only by the narrow Philippine island of Palawan.
China, the Philippines, Vietnam, Brunei, Malaysia and Taiwan have overlapping claims to parts of the South China Sea, which is believed to have vast oil and gas deposits, while its shipping lanes are vital for global trade.
Vietnam as well as the Philippines have in recent months accused China of taking increasingly aggressive actions in staking its claim to the disputed waters and its archipelagos.
In response, China has insisted it wants to resolve the territorial dispute peacefully but remained firm in its claims to most of the South China Sea, even waters within the Philippines' 200-nautical-mile economic exclusion zone.
Philippine President Benigno Aquino this month called for US help in containing China's South China Sea ambitions, saying his country was too weak to stand up to the Chinese alone.
Aquino made his plea after accusing China of inciting at least seven recent incidents in the disputed waters, including one in which a Chinese vessel allegedly opened fire on Filipino fishermen.
Aquino also accused China of breaking international law by entering the Philippines' economic exclusion zone.
US Secretary of State Hillary Clinton last week offered the Philippines some comfort, pledging that the superpower ally would help to modernise the cash-strapped Philippine military.
"We are determined and committed to supporting the defence of the Philippines," Clinton said.
No specifics were immediately announced but Philippine Foreign Secretary Albert del Rosario later said the US government had vowed to boost the Philippines' intelligence capabilities in the South China Sea.
The Philippine-US exercises, called Cooperation Afloat Readiness and Training (CARAT), officially begin at 3:00pm (0700 GMT) on Tuesday with an opening ceremony on Palawan island.
The first of the US vessels, the USS Chung-Hoon arrived at a pier in Palawan's capital, Puerto Princesa, on Tuesday morning, greeted by a Philippine Navy band playing marching tunes.
US sailors in dress uniforms stood to attention as their vessel was guided into place by tugboats. The second destroyer, the USS Howard, will arrive later in the day said Lieutenant Commander Mike Morley, spokesman of the US forces.
About 800 US sailors and 450 Philippine seamen will be involved in the exercises.
The United States is scheduled to stage similar exercises with Vietnam next month, although it has insisted they too are unrelated to the South China Sea tensions.
