BEIJING (Reuters) - China’s Defense Ministry said that a patrol by a U.S. warship in the South China Sea on Friday was “illegal” and “provocative” and that it had lodged a protest with the United States.

In a statement on its website, the ministry said two Chinese warships had warned the U.S. warship to leave during the patrol. It added that the Chinese military would increase air and sea patrols according to need.

U.S. defense officials said the guided-missile destroyer USS Decatur challenged “excessive maritime claims” in a patrol near the Paracel Islands, among a string of islets, reefs and shoals over which China has territorial disputes with its neighbors.

The Chinese Defense Ministry said two warships, the Guangzhou and the Luoyang, warned the U.S. vessel to leave.

It said China had declared its “baseline” for the Paracel Islands in 1996, something the United States was clear about. Despite that, the Chinese government said, the United States had sent a ship into Chinese “territorial waters.”

“This is serious illegal behavior, and is intentionally provocative behavior. China’s Defense Ministry is resolutely opposed to this and has lodged serious representations with the U.S. side,” it said.

The ministry statement said that as a result of hard work by countries in the region, the situation in the South China Sea had seen positive developments, but the United States had conducted the patrol, “motivated by a desire to see the world in chaos.”

“This shows that it is the United States which is the troublemaker when it comes to the stability of the South China Sea.”

The ministry said the patrol had seriously damaged mutual trust between the two countries and added:

“We strongly urge the U.S. side to respect China’s national sovereignty and security interests, and not keep repeating the same mistakes. The Chinese military will increase its air and maritime patrol efforts in accordance with need, strengthen defense ability building in all areas, and resolutely defend national sovereignty and security.”