Philippine President Rodrigo Duterte spent his first full day in China Wednesday, on a state visit that comes as he makes increasing overtures to Beijing while vocally scorning his US ally.

Since taking office on June 30, Duterte has repeatedly denounced the US and its President Barack Obama, suspended joint patrols in the South China Sea, and threatened further action, including an end to joint military exercises.

His posture is a stark reversal from the previous administration of Benigno Aquino, which took Beijing to an international tribunal over its extensive claims in the South China Sea and won a resounding victory.

Duterte initially took a hardline stance on the issue, vowing to ride a jet ski to the disputed Spratly Islands and plant his country's flag there.

But his bravado has since softened and he has shown no sign of seeking to enforce the tribunal ruling which infuriated Beijing.

Duterte will meet top leaders including President Xi Jinping and Premier Li Keqiang.

"Only China can help us," he told the official Xinhua news agency Monday.

He was due to meet members of the Filipino community in Beijing later Wednesday.

The Philippines is hoping, among other things, that Beijing will repeal a ban on imports of its bananas -- an economic sanction intended to punish Manila for its South China Sea stance.

The Philippines is one of several coastal nations which dispute China's claims to virtually all of the strategically vital waters. It has been a key player in the dispute, which is an issue of intense interest in both Washington and Beijing.

Tensions have risen between the US and China over Washington's "pivot" to the Asia-Pacific, a move which Beijing says is intended to contain its rise.

Duterte has said his trip will focus on promoting economic ties. Foreign affairs spokesman Charles Jose has said: "There will be a lot, I mean a lot, of business contracts that will be signed."

In an editorial Tuesday, China's nationalistic Global Times newspaper called on the government to "reciprocate Duterte's overture" by giving the Philippines access to fishing grounds near Scarborough Shoal -- a move which would imply that such rights were China's to give.

"Filipino fishermen fish on a shoestring and are unlikely to jeopardise the ecosystem of China's waters," the paper said.

China took control of the shoal in 2012 after a standoff with the Philippine navy. Manila has long claimed the feature for itself, maintaining that it controls the area's fishing rights.

China itself has been accused of doing massive environmental damage to the South China Sea by building artificial islands, some with airstrips, capable of hosting military facilities.

In another editorial Wednesday, the Global Times said Washington had treated Manila "as a pawn" and Duterte was "redesigning Philippine foreign policy based on Philippine interests".

Beijing has also enthusiastically endorsed Duterte's war on drugs, which has seen more than 3,700 people killed and led the International Criminal Court to warn that those responsible could face charges.

China, which has frequently been criticised for its own approach to drug users, "is his best partner in the anti-drug fight", the Global Times wrote.