t’s all in the name, according to President Rodrigo Duterte.
The fact that the South China Sea is named such reflects the historical claim of China to it, he said.

STATEMENT

In an ambush interview April 27 at Malacañang, Duterte told journalists:

“They really claim it as their own, noon pa iyan. Hindi lang talaga pumutok nang mainit. Ang nagpainit diyan iyong Amerikano. Noon pa iyan, kaya (It goes way back. The issue just did not erupt then. What triggered the conflict were the Americans. But it goes all the way back. That’s why it’s called) China Sea… sabi nga nila (they say) China Sea, historical na iyan. So hindi lang iyan pumuputok (It’s historical. The issue just had not erupted then) but this issue was the issue before so many generations ago.”

Source: Transcript of ambush interview, April 27, 2017, Presidential Communications Office News and Information Bureau
FACT

Contrary to Duterte’s statement, the body of water now commonly known as the South China Sea did not always have that name.

In his book The South China Sea Dispute: Philippine Sovereign Rights and Jurisdiction in the West Philippine Sea, Supreme Court Senior Associate Justice Antonio Carpio writes:

“Before Portuguese navigators coined the name South China Sea, the sea was known to Asian and Arab navigators as the Champa Sea, after the Cham people who established a great maritime kingdom in central Vietnam from the late 2nd to the 17th century.”
Carpio adds:

“The ancient Malays also called this sea Laut Chidol or the South Sea, as recorded by Pigafetta in his account of Ferdinand Magellan’s circumnavigation of the world from 1519 to 1522. In Malay, which is likewise derived from the Austronesian language, laut means sea and kidol means south.”

http://verafiles.org/articles/vera-files-fact-check-duterte-says-name-south-china-sea-refl