Lieutenant Commander Tim Gorman says the Chinese destroyer approached the USS Decatur in an "unsafe and unprofessional manoeuvre" on Sunday near Gaven Reefs.
Instead, it considers the waters and airspace to be worldwide and regularly conducts what it calls "freedom of navigation operations" in which warships and aircraft travel through disputed zones in order to demonstrate this. -China trade dispute. Each country has imposed tariff increases on the other's goods, and Beijing has accused the Trump administration of bullying.
In an official statement, the US Navy said Lanzhou came within 40m of the American vessel during the September 30 incident.
"U.S. Navy ships and aircraft operate throughout the Indo-Pacific routinely, including in the South China Sea", said Brown.
China claims most of the strategic waterway and has built islands on reefs and equipped them with military facilities such as airstrips, radar domes and missile systems.
USA officials have blasted the Chinese over the incident, complaining the Chinese ship approached the American warship in an "unsafe and unprofessional manner".
Meanwhile, US Defence Secretary James Mattis said on Monday he did not see Sino-US relations worsening, a day after his trip to China was cancelled. Washington has no official relations with Taiwan's democratically elected government but is obliged by USA law to see that it has the means to defend itself.
The US military is reportedly planning to send US warships, combat aircraft, and troops through the South China Sea and Taiwan Strait in November in a series of exercises created to send a message to Beijing.
'It seems to me that this was deliberate and could have been sanctioned by higher levels as part of the retaliatory moves by China in recent times'.
The Chinese Defense Ministry claimed its ship merely gave the U.S. Navy vessel "a warning to leave" after it entered the area "without permission".
Gaven Reef is one of seven Chinese-claimed outposts in the Spratlys Archipelago.
The Chinese military will fulfill its defense responsibility to safeguard its sovereignty and security as well as maintain regional peace and stability.
Mattis had originally planned to visit the Chinese capital to meet with senior Chinese officials to discuss security issues.
Military exchanges between the countries, including port calls, were temporarily suspended following a mid-air collision between a U.S. EP-3 spy plane and Chinese fighter in 2001 off the south China coast that sparked a major diplomatic row.
The bitter trade war between China and the United States will double to tensions in the military field, including a serious incident in the south China sea last weekend.
Two B-52s flew over the South China Sea last week in what the Pentagon called a routine mission.