USS McCampbell
© Reuters
FILE PHOTO: The Arleigh Burke-class guided-missile destroyer USS McCampbell in the South China Sea, January 15, 2019.
Two US warships have sailed through the South China Sea, a move that has angered Beijing. The naval maneuver comes a day after Donald Trump threatened China with more tariffs as part of an ongoing trade war.

The US military has confirmed that two of its warships sailed near islands claimed by Beijing in the South China Sea on Monday. China says the waterway is part of its territorial waters, while Washington insists that the sea is open to international transit under the principle of "freedom of navigation."

The US guided-missile destroyers 'Preble' and 'Chung Hoon' traveled within 12 nautical miles of Gaven and Johnson Reefs in the Spratly Islands, Reuters reported.

Chinese dredging vessels
© Reuters
Still image from United States Navy video purportedly shows Chinese dredging vessels in the waters around Mischief Reef in the disputed Spratly Islands, May 21, 2015
Commander Clay Doss, a spokesman for the Seventh Fleet, described the maneuver as "innocent," arguing that it served to "challenge excessive maritime claims and preserve access to the waterways as governed by international law."

The Chinese Navy reportedly asked the US vessels to leave.

"The relevant actions of the US warships violated China's sovereignty and undermined peace, security and good order in the relevant sea areas," Chinese foreign ministry spokesman Geng Shuang said at a press briefing.

"The Chinese side expresses strong dissatisfaction and resolute opposition" to the operation, Geng added, noting that the ships had entered the area "without permission."

The move comes hours after US President Donald Trump announced he would hike American tariffs on $200 billion worth of Chinese goods this week and target hundreds of billions more soon. The threat was made amid faltering negotiations between Washington and Beijing to end a months-long trade war.

The resource-rich South China Sea is the subject of conflicting claims by a number of countries, including China, Vietnam, the Philippines, Indonesia, Malaysia and Brunei. The US has been regularly sending its warships to carry out patrol missions in the disputed area, a policy decried by Beijing.

The South China Sea isn't the only waterway that has seen recent US activity. The White House announced on Sunday that it would deploy the USS 'Abraham Lincoln' Carrier Strike Group and a bomber task force to the Middle East, in an effort to "to send a clear and unmistakable message to the Iranian regime."