In a move that could heighten tensions between Washington and Beijing, two US Navy destroyers have sailed through the Taiwan Strait, a US Navy official has confirmed to CNN. The warships, the USS Mustin and USS Benfold, headed north, the official said, and are the first American warships to pass through the strait since July 2017, when the USS John S. McCain made the transit. The move, which several news outlets have reported, comes amid increasing strain between the Trump administration and China over trade, North Korea and the South China Sea. Pacific Fleet spokesman Capt. Charlie Brown called the passage of the ships “a routine transit.” “US Navy ships transit between the South China Sea and East China Sea via the Taiwan Strait, and have done so for many years,” Brown said. Beijing is perceived as sensitive to US military vessels traveling through the strait and continues to lay claim to Taiwan, a self-governed, democratic island, which it views as a breakaway province. The US Navy has not sailed an aircraft carrier in that area since 2007. China has boosted its own military presence in the region, sailing its own aircraft carrier through the strait in January. The Chinese military also recently conducted large-scale military exercises that analysts saw as a warning over growing ties between the United States and Taiwan. China and Taiwan have been governed separately since the end of the Chinese Civil War nearly 70 years ago. Although both Beijing and Taipei view the island as part of “China” – a term open to each side’s interpretation – neither government recognizes the legitimacy of the opposing side. The communist government in Beijing considers Taiwan a renegade province that must be reunited with the mainland, by force if necessary. Despite the lack of formal diplomatic ties, Taiwan remains an important American ally in the region, and the Trump administration has sought closer ties between Washington and Taipei. President Donald Trump made headlines when he became the first American president-elect to accept a congratulatory phone call from Taiwanese President Tsai Ing-wen. The US also continues to sell advanced weapons to Taiwan to aid in its defense as part of the requirements under the Taiwan Relations Act, actions that are met with condemnation from Beijing.