BEIJING -- Construction of artificial islands in the South China Sea has had little impact on local coral reef ecosystems, according to a government spokesman on Friday.

Foreign Ministry spokesperson Hong Lei was speaking in response to concerns voiced in the United States and the Philippines.

"The Nansha Islands are Chinese territory. China cares more about the environment of the reefs and waters in the vicinity than any other country, institution or individual," he said at a regular news briefing.

China wants the development of the islands to be sustainable and has taken measures to assure the integrity of the local environment and minimize the impact on reefs, Hong said.

"The projects will greatly improve the protection of the reefs and islands and will stand the test of time," he added.

Construction on the Nansha Islands and reefs includes lighthouses, weather stations, observation centers and research facilities.