The new U.S. administration of President Donald Trump vowed on Monday that the United States would prevent China from taking over territory in international waters in the South China Sea, something Chinese state media has said would require Washington to "wage war."

"I think the U.S. is going to make sure that we protect our interests there," White House spokesman Sean Spicer told a news briefing.

"It’s a question of if those islands are in fact in international waters and not part of China proper, then yeah, we’re going to make sure that we defend international territories from being taken over by one country."

Spicer was responding to a question as to whether Trump agreed with comments by his Secretary of State nominee, Rex Tillerson, on Jan. 11 that China should not be allowed access to islands it has built in the contested South China Sea.

Tillerson's remarks at his Senate confirmation hearing prompted Chinese state media to say the United States would need to "wage war" to bar China's access to the islands where it has built military-length air strips and installed weapons systems.