Hua Chunying, spokeswoman of China's Foreign Ministry, speaks at a regular news conference in Beijing, China, January 6, 2016. Photo: Reuters

China said on Tuesday it had "irrefutable" sovereignty over disputed islands in the South China Sea after the White House vowed to defend "international territories" in the strategic waterway.

Chinese Foreign Ministry spokeswoman Hua Chunying told a regular news briefing on Tuesday, "The United States is not a party to the South China Sea dispute."

Hua was responding to comments made by White House press secretary, Sean Spicer, the previous day.

"The U.S. is going to make sure that we protect our interests there," Spicer said when asked if President Donald Trump agreed with comments by his secretary of state nominee, Rex Tillerson. On Jan. 11, Tillerson said China should not be allowed access to islands it has built in the contested South China Sea.

He likened China's island-building in the South China Sea to "Russia's taking of Crimea," and said the new US government would send China a clear signal that "first the island building stops, and second your access to those islands is also not going to be allowed."

"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 said.

China's sovereignty over the Spratly Islands in the South China Sea was "irrefutable," Hua said. But China was also dedicated to protecting freedom of navigation and wants talks with nations directly involved to find a peaceful solution.

"We urge the United States to respect the facts, speak and act cautiously to avoid harming the peace and stability of the South China Sea," Hua said.

"Our actions in the South China Sea are reasonable and fair. No matter what changes happen in other countries, what they say or what they want to do, China's resolve to protect its sovereignty and maritime rights in the South China Sea will not change," she added.