Aquino said he hoped his talks with visiting Defence Minister Liang Guanglie would help to avoid a real conflict over the chain of islands in the South China Sea which both countries claim.
"In the interest of maintaining good bilateral relations, we will express our feelings and ask them how we should look at these incidents," he told reporters.
"The end point of this is hopefully to minimise such incidents before we have a real conflict," Aquino said, a day after Liang arrived in the Philippines on a four-day visit.
Aquino cited an incident in March when two Chinese vessels shadowed a Philippine oil exploration vessel while it was in the Spratlys.
He also cited an incident earlier this month when two foreign fighter jets flew near two Philippine air force OV-10 Bronco turboprops in the area.
Local press reports have said the jets were Chinese but the military would not confirm this.
Aquino said the incidents showed the need to have a legally binding "code of conduct" to prevent any conflicts over the territorial dispute between ASEAN members and China in the South China Sea.
The Association of Southeast Asian Nations has been pushing China to agree to a binding "regional code of conduct" that will govern actions in the South China Sea.
This would replace a non-binding "declaration" by the claimants not to take destabilising actions in the area but China has been reluctant to engage in multilateral talks with ASEAN.
The reputedly oil-rich chain of islands is claimed in whole or in part by China and the Philippines as well as Brunei, Malaysia, Taiwan and Vietnam.
The Philippines, Brunei, Malaysia and Vietnam are all members of ASEAN. (*)
Editor: Kunto Wibisono
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