President Rodrigo Duterte returned early Sunday from a five-day "successful and highly productive" trip to China, Malacanang said.

Duterte arrived at around 2am at Villamor Air Base in Paranaque City from Guangzhou Baiyun International Airport in Guangdong Province in China.

“With the conclusion of President Duterte’s official visit to China, we wish to inform the public that the same has been successful and highly productive,” Presidential Spokesperson Salvador Panelo said in a statement.

He said the close relationship through the years between Duterte and Chinese President Xi Jinping has enabled the two leaders to have frank exchanges on the respective positions regarding the territorial dispute in the South China Sea.

During his bilateral talks with Xi, Duterte brought up the Hague award on the Philippines, invalidating China's historic and sovereign claim over almost the entire South China Sea through nine-dash line.

But Xi reiterated China's rejection over the United Nations arbitral ruling.

Panelo said the two leaders have agreed "to exercise self-restraint and observe the UNCLOS (United Nations Convention on the Law of the Sea), particularly with respect to maritime navigation and overflight in the South China Sea, and with China’s recognition of the immediate need of the crafting of a definitive Code of Conduct for our regional waters, all with the intent of avoiding provocative acts that may impair friendly ties and threaten the peace and stability of the region."

Six agreements were also signed during Duterte's fifth visit to China, covering cooperation in the areas of education, science and technology, finance, and customs, among others.

Aside from Xi, the Filipino leader also had bilateral talks with Chinese Premier Li Keqiang. He also watched the FIBA Basketball World Cup Game between the Philippines and Italy and officially received a courtesy call from Chinese Vice President Wang Qishan.

Duterte also met with Chinese and Filipino investors, including key business leaders in the Philippine construction industry, during the Philippines-China Business Forum organized by the Department of Trade and Industry. Ella Dionisio/DMS