China's military said it "drove away" a U.S. warship that illegally entered Chinese waters near the Paracel Islands on Monday, the anniversary of an international court ruling that favored Manila and said Beijing had no claim over the South China Sea.
The USS Benfold entered the waters without China's approval, seriously violating its sovereignty and undermining the stability of the South China Sea, the southern theatre command of the People's Liberation Army said.
"We urge the United States to immediately stop such provocative actions," it said in a statement.
On July 12, 2016, the Permanent Court of Arbitration in the Hague ruled that China had no historic title over the South China Sea, a ruling that China said it would ignore. The late Philippine President Benigno "Noynoy" Aquino initiated the case but the verdict was handed down durint the term of his successor, President Rodrigo Duterte.
The Benfold asserted navigational rights and freedoms in the vicinity of the Paracel Islands consistent with international law, the U.S. Navy said in a statement on Monday.
The islands are claimed by China, Taiwan and Vietnam, which require either permission or advance notification before a military vessel passes through.
"Under international law as reflected in the Law of the Sea Convention, the ships of all states, including their warships,- enjoy the right of innocent passage through the territorial sea," the U.S. Navy added.
"By engaging in innocent passage without giving prior notification to or asking permission from any of the claimants, the United States challenged these unlawful restrictions imposed by China, Taiwan and Vietnam."
Hundreds of other islands, reefs and atolls in the resource-rich waterway are contested by Brunei, China, Malaysia and the Philippines, with China claiming rights to resources within its so-called nine-dash line, or most of the region.
"By conducting this operation, the United States demonstrated that these waters are beyond what China can lawfully claim as its territorial sea, and that China's claimed straight baselines around the Paracel Islands are inconsistent with international law," the U.S. Navy said.
In its 2016 ruling, the Hague court also said China had interfered with traditional Philippine fishing rights at Scarborough Shoal and breached the country's sovereign rights by exploring for oil and gas near the Reed Bank.
Freedom of the seas was an "enduring" interest of all nations, U.S. Secretary of State Antony Blinken said on Sunday.
"Nowhere is the rules-based maritime order under greater threat than in the South China Sea," Blinken said in a statement.
"The People's Republic of China continues to coerce and intimidate Southeast Asian coastal states, threatening freedom of navigation in this critical global throughway."