The Chinese military recently warned a US guided-missile destroyer to "withdraw" from waters in the disputed South China Sea, raising tensions with the Americans, especially after the Chinese President's trip to Moscow.
The Chinese claims are dismissed as "false" by US forces.
China is known to claim sovereignty over almost the entire South China Sea, a strategic waterway through which hundreds of ships bringing in trillions of dollars a year pass, despite an international court ruling that the claim has no legal basis.
The Philippines, Vietnam, Malaysia and Brunei all have overlapping claims in this sea, while the United States sends its Navy ships there to assert freedom of navigation in international waters.
China's People's Liberation Army (PLA) Southern Sector Naval Command officially announced that the USS Milius, a guided-missile destroyer, entered waters around the Paracel Islands, which are also claimed by Vietnam, on Thursday.
"Chinese aircraft, warships and drones are closely monitoring (the US destroyer) in accordance with the law" while we have warned it to leave, Chinese spokesman Tian Junli said.
The vessel "made an illegal incursion into Chinese territorial waters... without permission from the Chinese government, harming peace and stability" in the region, the Chinese Navy spokesman concluded.
The US Navy immediately denied the claims, telling AFP that "the Chinese statement is false," using the acronym for the People's Republic of China.
“Our vessel is conducting routine operations in the South China Sea and will not leave if it is expelled. The United States will continue to fly, sail and operate wherever international law permits," said the US Pacific Command spokesman.
The tension in the region is in the "red", since neither the Chinese nor the Americans are "backing down", in a situation that is a test for both countries.
While staking their claims in the South China Sea, Chinese authorities have in recent years built artificial islands, including some with military installations and runways.
Regional countries have also accused Chinese vessels of harassing their fishing vessels.
We also remind that the so-called Chinese neutrality towards the war in Ukraine is now being refuted, since it shows that despite the lack of supplies of large weapons and lethal systems, Beijing still supports Russia, enabling the acquisition of drones in large numbers, angering the US.