CNN  — 

A US destroyer has sailed within 12 nautical miles of a Chinese-claimed island in the South China Sea, a highly-contested stretch of water where China’s been reclaiming land and building islands, US officials told CNN Friday.

In its own statement late Friday, China’s defense ministry said two Chinese Navy ships “took immediate action to identify and verify the US ship, and warned and dispelled it.”

“China holds indisputable sovereignty over the islands and their surrounding waters in the South China Sea,” ministry spokesman Ren Guoqiang said in a statement. “By repeatedly sending military ships into these areas without authorization, the US has seriously harmed Chinese sovereignty and security, violated basic rules of international relations, and harmed regional peace and stability,” the spokesman said.

China’s defense ministry claimed that by carrying out these so-called infringements, the US had “damaged the atmosphere of military-to-military relations between the two countries, caused close encounters by air and naval forces, which could easily trigger miscalculation or even accidents at sea or in air.”

The defense ministry called the American behavior a “serious political and military provocation against China. The Chinese military is firmly opposed to it.”

The US Navy conducts regular Freedom of Navigation operations in the region with the unstated goal of challenging China’s huge, disputed territorial claims in the South China Sea.

On Friday, the USS Mustin sailed close to Mischief Reef in the Spratly Islands, an island chain also claimed by the Philippines, a US defense official told CNN.

“All operations are designed in accordance with international law and demonstrate that the United States will fly, sail and operate wherever international law allows,” Lt. Cdr. Nicole Schwegman, US Pacific Fleet spokeswoman, said.

The Chinese government has laid claim a large swathe of territory in the region, overlapping areas claimed by other countries including Vietnam and the Philippines.

To reinforce its position, Beijing has reclaimed land and constructed military assets on a series of reefs in the Spratly and Paracel island chains in the South China Sea.

In October 2017, the US Navy destroyer USS Chafee also sailed close to the Paracels, provoking a stern reaction from the Chinese Defense Ministry. “(We are) firmly opposed to such flaunting of force and promotion of militarization in the region by the US, which could easily trigger accidents at sea and in the air,” it said in a statement at the time.

On Friday, the Chinese Navy announced it would hold live fire drills in the South China Sea at an undisclosed date and location.

According to state media, the navy will hold the drills “in the near future” but didn’t elaborate further on their timing or what they would entail.

“The purpose is to test and improve the training level of the troops and comprehensively improve the ability to win,” state media said.

The drills do “not target any particular country,” the report added.

For many years the South China Sea has been considered an international flashpoint, as the US and China attempt to assert their influence in the region.

But the ongoing nuclear crisis in North Korea and a distracted US government under President Donald Trump has diverted attention from the area, allowing the Chinese government to tighten its hold.

“The Chinese continue to pace with their long-term strategy to gain de facto control over the sea lanes in the South China Sea. And what changed is the United States stopped paying attention,” Michael Fuchs, a senior fellow at the Center for American Progress, told CNN in December.

Correction: The story has been corrected to state that US defense officials confirmed the operation Friday.