An airstrip, structures and buildings on China's man-made Subi Reef in the Spratly chain of islands in the South China Sea are seen from a Philippine air force C-130 transport plane in April. (Bullit Marquez/AP)

China’s military vowed Monday to step up air and sea patrols after an American warship sailed near a disputed island in the South China Sea in what Beijing called a “serious political and military provocation.”

The spat is the latest in a series of disputes that have roiled the U.S.-China relationship in just the past few days. Experts said Washington appeared to be signaling its growing frustration with Beijing by rolling out measures including arms sales to Taiwan and sanctions against a Chinese bank doing business with North Korea.

On Sunday, the USS Stethem, a guided-missile destroyer, sailed within 12 nautical miles of Triton Island, a U.S. defense official said. The small isle in the Paracel Islands chain is claimed and controlled by China. It was the second such U.S. operation near Chinese-controlled islands in six weeks.

U.S. officials tried to portray the latest patrol as a routine, planned maneuver, but whatever their intentions, it has created more friction between the two countries. China’s Defense Ministry said its armed forces had dispatched two frigates, a minesweeper and two fighter jets to warn the Stethem away.

A senior administration official said the White House did not believe the freedom of navigation operation came as a surprise to Beijing. “It’s actually routine activity,” the official said, speaking on the condition of anonymity about sensitive bilateral relations. “We made that very clear to them. I don’t see anything that suggests either side is moving to destabilize the situation.”

(Reuters)

Trump hosted Chinese President Xi Jinping at his Mar-a-Lago resort in April and said the men enjoyed “great chemistry.” That marked a reversal from his tone during the presidential campaign, in which he had assailed China for what he called its unfair trade and currency practices. But in recent weeks, the White House has become frustrated with China over its reluctance to tighten the screws on North Korea in retaliation for its nuclear and missile program. China is North Korea’s biggest trading partner.

“No more relying on the bromance between Donald and Jinping,” Evan Medeiros, who served as President Barack Obama’s top adviser for Asia, said in an interview. “The honeymoon is clearly over, but the next phase is less clear.”

Last week, the United States angered China by lumping the country with the world’s worst offenders on human trafficking, a downgrade from previous years. It was the new administration’s most strident public criticism yet of China’s human rights record.

Medeiros said Washington was sending a signal that policy toward China was changing, with the ultimate aim of securing more cooperation from Beijing.

The Paracels are among a group of islands and atolls in the South China Sea at the heart of ongoing tensions in Southeast Asia. China claims full sovereignty over the sea and has built military facilities on some islands.

The White House, in the Obama and Trump administrations, has seen the militarization of the South China Sea as a threat to stability in the resource-rich region, where ships from numerous countries have long fished.

[China to U.S.: New sanctions, arms sales to Taiwan the ‘wrong moves’]

China’s Defense Ministry said the United States has “seriously damaged strategic mutual trust” between the two countries by entering what it claimed were China’s territorial waters, while the country’s Foreign Ministry accused the United States of staging a “serious political and military provocation.”

The incident came just hours before Trump spoke by telephone to Xi — on Sunday night in Washington, Monday morning in Beijing.

During the call, Trump “raised the growing threat posed by North Korea’s nuclear and ballistic missile programs,” the White House said in a statement.

Xi also used the call to express his concerns, requesting that the United States “handle the Taiwan issue appropriately,” according to a Chinese statement. China considers Taiwan a renegade province.

“Xi stressed that both China and the United States need to control the general direction of the bilateral relationship in light of the consensus reached at the Mar-a-Lago summit,” China’s government said.

Neither statement mentioned the tensions over the South China Sea.

The senior administration official called the call a “clearing of the air.”

China had appeared confident that it had reached an understanding with the United States after the Mar-a-Lago meeting and had gauged the minimum necessary action required to satisfy the Trump administration, said Bonnie Glaser, a senior adviser for Asia at the Center for Strategic and International Studies. Chinese leaders seemed to have miscalculated.

“Apparently, they didn’t respond adequately to U.S. concerns about banks and front companies in China that are enabling North Korea’s illegal activities,” she said.

A downturn in ties was effectively announced on Twitter on June 20, when Trump declared that China’s pressure on North Korea had “not worked out.”

Arthur Kroeber, managing director of Gavekal Dragonomics, a consulting and research firm, said Trump may have miscalculated, too.

“The basic deal Trump thought he offered Xi at the Mar-a-Lago summit — a light touch on trade in exchange for more cooperation on North Korea — was absurdly unrealistic, given China’s obvious unwillingness to change its North Korea policy,” he wrote in a client note.

But Kroeber said he still did not expect Trump to embark on a “stupid and self-defeating trade war” with China.

“The more likely outcome is that he will settle for largely symbolic actions” that will “do little to change trade flows but enable him to crow to his political base that he has got tough with foreigners who are cheating Americans out of production and jobs,” he wrote.

Chinese Foreign Ministry spokesman Geng Shuang said at a news conference Monday that both sides were “determined to press ahead” with their relationship despite encountering “some issues.”

A Chinese foreign policy expert, speaking on the condition of anonymity because he was not authorized to speak to the media, said Beijing does not want to see a deterioration in relations with Washington before an important Communist Party congress in the fall that is due to formally award Xi a second five-year term as leader.

“Facing America’s recent behavior, the Chinese government had to make a public response,” he said. “But President Xi’s words were relatively low-key.”

U.S. officials said the Navy’s action Sunday — known as a freedom-of-navigation operation, or FONOP — was not aimed at making a political statement.

[Opinion: Chinese-U. S. honeymoon is over]

China has had de facto control of the Paracels since expelling Vietnam in 1974.

The Foreign Ministry said the Stethem had “trespassed” there, entering the waters “without China’s approval.” Wu Qian, a spokesman for the Defense Ministry, said the American action seriously damaged strategic mutual trust and military relations.

“The Chinese army will strengthen its defense capacity, increase the intensity of its sea and air patrols, and firmly defend national sovereignty and security,” he said in a statement.

In May, a U.S. destroyer sailed within 12 miles of Mischief Reef, a man-made island in the Spratly Islands to the south of the Paracels.

[Satellite images show reinforced Chinese missile sites near disputed islands]

The 12-mile line is the internationally recognized distance that separates the shores of a sovereign nation from international waters. The United States has routinely conducted voyages within this 12-mile limit around islands in the South China Sea as a message to countries such as China, Taiwan, Vietnam and the Philippines.

Many of these nations have laid claim to islands in the South China Sea, some of which are no more than tiny strips of sand and reef.

The Stethem, an Arleigh Burke-class destroyer, is based in Japan.

Gibbons-Neff reported from Boston. David Nakamura in Washington contributed to this report.

Read more:

Taiwan arms sale, N. Korea sanctions outrage Beijing in test of U.S.-China ties under Trump

How China’s fishermen are fighting a covert war in the South China Sea

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