The US Navy is preparing to sail a warship close to artificial islands built by China in the South China Sea, a move the Asian power has dubbed a "provocation".
US officials told Associated Press on Monday that the White House approved the movement by the USS Lassen, a guided missile destroyer, around the Spratly Islands archipelago, a disputed group of hundreds of reefs, islets, atolls and islands in the South China.
Freedom of navigation and overflight should not be used as excuse to flex muscle and undermine other countries' sovereignty and security
Spokesperson, Chinese embassy in Washington
The officials spoke on condition of anonymity because they were not authorised to discuss the matter in advance of the Lassen's movement.
A Pentagon spokesman, Navy Cmdr Bill Urban, declined to comment.
Tensions have mounted since China transformed reefs in the area - also claimed by several neighbouring countries - into small islands capable of supporting military facilities, a move the US says threatens freedom of navigation.
'Muscle-flexing'
The Chinese Embassy in Washington, responding to the naval movement, said the concept of freedom of navigation should not be used as excuse for muscle-flexing.
Embassy spokesman Zhu Haiquan told Reuters that the United States should "refrain from saying or doing anything provocative and act responsibly in maintaining regional peace and stability".
"Freedom of navigation and overflight should not be used as excuse to flex muscle and undermine other countries' sovereignty and security," he said.
Washington has repeatedly said it does not recognise Chinese claims to territorial waters around the artificial islands.
"We operate routinely in the South China Sea and we'll sail in international waters at a time of our choosing," another official told AFP news agency.
President Barack Obama administration has long said it will exercise a right to freedom of navigation in any international waters, including in the South China Sea.
State Department spokesman John Kirby said on Monday that the US would not be required to consult with other nations if it decided to conduct freedom of navigation operations in international waters anywhere on the globe.
Strategically vital waterway 
"Make no mistake, the United States will fly, sail and operate wherever international law allows, as we do around the world, and the South China Sea is not and will not be an exception," Defense Secretary Ash Carter said on October 13.
"We'll do that at times and places of our choosing," Carter said. "And there's no exception to that, whether it's the Arctic or the sea lanes that fuel international commerce widely around the world, or the South China Sea."
Beijing insists it has sovereign rights to nearly all of the South China Sea, even waters close to the coasts of other states.
The sea is a strategically vital waterway with shipping lanes through which about a third of all the world's traded oil passes, and the dispute has raised fears of clashes.
Satellite images of the islands show that China has reclaimed millions of square meters of land in the Spratlys, known as Nansha in Chinese.
Imagery also shows China has built a host of facilities, including as many as three runways.
An editorial in the Global Times, which is close to China's ruling Communist party, this month condemned Washington's "ceaseless provocations and coercion" and said the Chinese military should use force if the United States "encroaches on China's core interests".
Brunei, Malaysia, the Philippines and Vietnam - members of the Association of Southeast Asian Nations - also claim parts of the sea. Taiwan is a sixth claimant.
The USS Lassen is anchored in Yokosuka near Tokyo (Koji Sasahara/AP File photo]