(Bloomberg) -- China criticized the US after an American warship sailed in disputed waters in the South China Sea, underscoring lingering military tensions between the nations.

The appearance of the USS Gabrielle Giffords near the Second Thomas Shoal on Monday “seriously violated China’s sovereignty and security,” according to a statement from the Chinese military.

The littoral combat ship “undermined regional peace and stability,” the military added, “demonstrating that the US is the biggest threat to peace and stability” in the region.

The US vessel “was conducting routine operations in international waters” that followed international law, Commander Megan Greene of the US Seventh Fleet said in a statement. “We will not be deterred from continuing to work alongside our allies and partners in support of our shared vision for a free and open Indo-Pacific,” she added.

While a meeting in the US last month between President Joe Biden and Chinese leader Xi Jinping helped stabilize overall ties, the two nations remain at odds over American military activity. Top-level military links have been cut since then-House Speaker Nancy Pelosi visited Taiwan in August 2022, a trip the People’s Liberation Army responded to with unprecedented military drills.

While US officials said China agreed in the Xi-Biden sitdown to policy-level discussions with Defense Secretary Lloyd Austin, Beijing has yet to name a replacement for ousted Defense Minister Li Shangfu. The continued lack of communication raises the risk that an accident in the South China Sea could spiral into a conflict.  

See: China, US Release Dueling Videos With Accusations of Provocation

In October, the US and China each released video footage they said showed provocative or unprofessional actions by military craft in and around the body of water that Beijing claims mostly as its own.

The Second Thomas Shoal is the site of recent tense encounters between Chinese and Philippine vessels over a World War II-era ship that Manila placed in the shoal more than two decades ago. The Philippines said that move was in response to China’s occupation of nearby reef.

Also: A Rusty, Stranded Ship Is Fueling China and Philippine Tensions

The Philippines’ coast guard said Sunday that it monitored more than 135 Chinese “maritime militia” vessels around the Whitsun Reef, which is just west of the Second Thomas Shoal.

(Updates with comments from US Seventh Fleet and more context.)

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