ZHANJIANG, China - US and Chinese sailors faced off on Chinese soil Tuesday, in sporting clashes between their giant militaries aimed at building trust against a backdrop of tensions over Beijing’s assertion of its territorial claims.

The contests - the hosts claimed a 3-1 victory at football, but the visitors dominated on the basketball court - came as the USS Blue Ridge, the flagship of the US Navy’s 7th Fleet, paid a rare visit to the base of China’s South Sea Fleet.

Its frigates are charged with defending Beijing’s claim to almost all the South China Sea, against several Southeast Asian neighbours.

Chinese officers toured the hulking visiting command ship, docked beside People’s Liberation Army vessels in Zhanjiang, in the southern province of Guangdong, and later eyed up their US counterparts over lunch.

On the Blue Ridge’s main deck, US personnel patrolled with M-16 rifles a stones’ throw from the palm-fringed Chinese shore, while on land staff from both navies swapped jokes and rebounds.

The Chinese and US militaries - the world’s largest and most powerful respectively - have been increasing exchanges even as Beijing’s assertion of its South China Sea claims, most recently through rapid building of artificial islands, raises alarm bells in Washington.

US Admiral Harry Harris, commander of the US Pacific Fleet of which the 7th Fleet is a part, said Tuesday: “China is responsible for the rise of tensions and provocations in the South China Sea.”

“I don’t think that there’s a likelihood of a major force-on-force conflict in the South China Sea today,” he added while visiting the Indonesian capital Jakarta. “But I have to be ready for that.” The South China Sea is a vital strategic waterway and close encounters between the two powers’ ships have led to fears of a clash.

In their most serious maritime incident for years, a US guided missile warship, the Cowpens, had to make a sharp turn to avoid colliding with a Chinese naval ship that cut in front of it in the South China Sea in 2013, according to the Pentagon.

Meanwhile, the Philippines said Tuesday it would soon ask the United States for more military equipment and training to build its defences, as it faces Chinese “aggressiveness” in disputed waters.

As hundreds of Filipino and American Marines simulated an amphibious assault to reclaim territory from invaders during annual war games, military chief General Gregorio Catapang told AFP he was drafting a “wish list” for US aid.

Catapang said the Philippines would ask for “equipment and training”, when Foreign Affairs Secretary Albert del Rosario travelled to the US in about a week’s time.

“The US has told us that they will help us develop our capabilities, and now, we are focused on maritime security,” Catapang said as he watched tanks emerge from the sea and roll onto the beach.

“We want to have capability on wetland, marshland, and beach landings,” he said when asked to elaborate on the contents of the “wish list”.

He said he hoped the US military would train his men on the operation of amphibious tanks, which the Philippines is buying for the first time this year as part of a defence upgrade.

The US is already the biggest military supplier to the Philippines, a former colony to which it remains allied by a mutual defence treaty.

Tuesday’s drills, among the first of annual war games between the allies, took place 220 kilometres (137 miles) east of the Scarborough Shoal in the South China Sea.

The shoal is a rich fishing ground China has controlled since the end of a maritime standoff with the Philippines in 2012.

Presidential spokesman Herminio Coloma alleged on Monday that a Chinese vessel recently used a water cannon to drive Filipino fishermen away from the shoal.

On Monday, Catapang criticised China’s “aggressiveness” as he showed satellite photos of “massive” reclamations on seven reefs in the South China Sea.

China claims almost the entire South China Sea, home to vital shipping lanes and also believed to hold vast mineral reserves.

The Philippines, Vietnam, Malaysia, Brunei and Taiwan also have often overlapping claims.

During Tuesday’s drills, 21 amphibious tanks rolled out of the US Navy’s giant warship USS Green Bay to battle troops from the fictitious country “Calabania”, which invaded a Philippine island.

As the first batch of tanks approached the beach, they created a smokescreen setting fire to diesel to hide the others moving behind them. Six attack helicopters flying overhead provided air support.

The tanks then beached and marines in full battle dress swiftly ran ashore and advanced inland. Troops fired mortar rounds towards enemy positions to make way for the ground assault.