The Chinese military on Monday vowed to increase air and sea patrols after a United States warship sailed close to a disputed island in the South China Sea, The Washington Post reported. The military called the US action a “serious offence” and China’s defence ministry said the US had “seriously damaged strategic mutual trust” between the two countries by entering what it claimed were China’s territorial waters.

Meanwhile, the country’s foreign ministry accused the United States of staging a “serious political and military provocation.” The statements came just after US President Donald Trump spoke over the telephone to Chinese President Xi Jinping on Sunday night.

In the meeting, Xi complained to Trump about “negative factors” undermining relations between the two countries. “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,” a Chinese statement said.

Trump, on the other hand, “raised the growing threat posed by North Korea’s nuclear and ballistic missile programmes,” the White House said in a statement. But Xi requested the US President to “handle the Taiwan issue appropriately”. Xi was referring to the United States announcing an arms deal worth $1.42 billion (Rs 91 billion) with Taiwan and sanctioning a Chinese bank for doing business with North Korea.

However, the immediate “provocation” for China’s decision to increase sea and air patrols was the US destroyer USS Stethem, which passed less than 12 nautical miles (22 kilometers) from Triton Island in the Paracel Islands archipelago, which is also claimed by Taiwan and Vietnam besides China.

China has accused the United States of deliberately stirring up trouble in the South China Sea and staging “provocative operations” that violate China’s sovereignty. China’s foreign ministry claimed that the USS Stethem had “trespassed” there, entering the waters “without China’s approval”.