Philippines to partner with China in oil exploration at South China Sea.

Philippine President Rodrigo Duterte said his government was in talks with China over joint drilling for natural resources in the South China Sea.

The Philippines tried Wednesday to reassure Southeast Asian neighbours about its proposal to partner with Beijing in oil exploration in the disputed South China Sea, promising to consult them on any plans.

President Rodrigo Duterte has softened his predecessor's policy opposing China's claims which expand to nearly the entire sea causing alarm among neighbouring Southeast Asian countries, which also hold partial claims.

On Monday Duterte said his government was in talks with China over joint drilling for natural resources in the sea, reversing years of tensions.

But Foreign Secretary Alan Peter Cayetano said Wednesday the Philippines would consult its nine fellow Association of Southeast Asian Nations (ASEAN) members about the proposal.

"It will not be a unilateral action from the Philippines because the premise of the president is peace and stability, and unilateral action by anybody leads to destabilisation," he told reporters.

"There will also have to be consultations with the whole ASEAN because we want to keep the stability there."

Duterte, 72, has played down his country's maritime dispute with China in favour of billions of dollars in trade and investment from Beijing.

He has also refused to use as leverage a UN-backed tribunal's ruling last year which rejected Beijing's claims to most of the sea.

His predecessor Benigno Aquino had sought the ruling and in 2015 suspended Philippine exploration activities at Reed Bank, where Manila's claims overlap those of China.

Under Aquino the Philippines had forcefully challenged China through legal and diplomatic avenues including ASEAN events.

Aquino rallied ASEAN to put up a united front against Beijing's reclamation and island-building activities in the sea a policy that Duterte reversed.

At an April summit ASEAN under Duterte's chairmanship released a statement that failed to condemn China's push to control most of the sea.

The South China Sea will be on the agenda as Cayetano meets his ASEAN counterparts in Manila next week.

Cayetano refused to say if the joint China-Philippines oil and gas exploration would be in specific areas of the sea also claimed by ASEAN members Vietnam, Malaysia and Brunei.

Taiwan also claims almost the entire area, which is believed to sit atop vast oil and gas reserves, but is not an ASEAN member.

Negotiations for a joint exploration had "peaked" during Duterte's visit to Beijing in May where he told Chinese President Xi Jinping that he intended to drill for oil in the South China Sea, according to Cayetano.

Chinese Foreign Minister Wang Yi, visiting Manila on Tuesday, said Beijing was open to joint development.