Based on a senior American official China examined numerous anti-ship ballistic missiles during the weekend.
Pentagon spokesman Lieutenant Colonel Dave Eastburn commented: “Of course the Pentagon was aware of the Chinese missile launch from the man-made structures in the South China Sea close to the Spratly Islands.
“I’m not going to speak on behalf of all the sovereign nations in the region, but I’m sure they agree that the PRC’s behavior is contrary to its claim to want to bring peace to the region.
“Obviously actions like this are coercive acts meant to intimidate other (South China Sea) claimants.”
The US President said the demonstrators were “looking for democracy” before adding “some governments don’t want democracy.
Trump has also imposed several trade sanctions on Chinese goods, after accusing the country of unfair practice.
However he agreed not to place additional sanctions during a G20 meeting with Chinese leader Xi Jinping in Japan.
China has been building military facilities on islands and artificial reefs in the South China Sea.