On May 25, the USS Dewey guided-missile destroyer sailed less than 12 nautical miles from Mischief Reef - part of the disputed Spratly Islands in the South China Sea, south of the Paracel Islands.
China claims most of the south China sea, including areas very close to the coast of many countries of South-East Asia.
Freedom of navigation patrols (FONOPS) represent "a challenge to excessive maritime claims", according to the U.S. Defense Department.
Twelve nautical miles marks the territorial limits recognised internationally.
"Fake islands should not be believed by real people", Harris said, apparently referring to the artificial islands being built by China in the disputed South China Sea.
In recent months, Trump has approached a traditional foe, Chinese President Xi Jinping, to assist in USA -led efforts to disarm North Korea's nuclear weapons arsenal.
All those steps added up to a sharp reversal in tone from April, when Xi traveled to Trump's Mar-a-Lago resort in Florida for a first face-to-face meeting that Trump later said had helped build an "outstanding" relationship.
"The Chinese side strongly urges the United States side to immediately stop such kind of provocative operations that violate China's sovereignty and threaten China's security", Kang said in the statement.
Trump on Thursday authorized a $1.3 billion arms sale to Taiwan, which China considers a rebel province.
A spokesman for the U.S. Pacific Fleet, Lt. Cmdr.
"The United States will fly, sail and operate wherever global law allows", he told USA Today. The White House, in both the Obama and Trump administrations, has seen the militarisation of the South China Sea as a threat to stability in the resource-rich region, where ships from numerous countries have long fished.
China has continued to militarize its outposts there - despite a pledge to the contrary - as it seeks to reinforce effective control of much of the waterway, through which $5 trillion in trade passes each year.
Triton Island is claimed by China, Vietnam and Taiwan. "That is true in the South China Sea as in other places around the globe".
Construction is shown on Mischief Reef, in the Spratly Islands, the disputed South China Sea in this June 19, 2017 satellite image released by the Asia Maritime Transparency Initiative (ATMI) at the Center for Strategic and International Studies (CSIS) to Reuters on June 29, 2017. Beijing has called the moves purely defensive.
China has built new military facilities on islands in the South China Sea, a U.S. think tank reported on Thursday, a move that could raise tensions with Washington, which has accused Beijing of militarising the vital waterway.
AMTI reported in February that Mischief and Subi Reefs each have eight "hardened" shelters with retractable roofs.