TAIPEI (Taiwan News) – The U.S. military confirmed that two of its warships sailed near islands claimed by China in the South China Sea on Monday, May 6.

A U.S. military spokesman told Reuters that the two warships were the destroyers USS Preble and USS Chung Hoon. Commander Clay Doss, a spokesman for the Seventh Fleet, said the “innocent passage” was “to challenge excessive maritime claims and preserve access to the waterways as governed by international law.”

The two U.S. destroyers crossed the South China Sea right after President Donald Trump announced on Sunday (May 5) that tariffs on Chinese high tech goods and other goods will soon go up, increasing tensions between the world’s two biggest economies.

China has been building military installations on artificial islands and reefs in the South China Sea, while slamming the United States and its allies over naval operations near islands claimed by China, reported Reuters.

The operation carried out by the destroyers, USS Preble and USS Chung Hoon, is the latest attempt to counter what Washington sees as Beijing’s efforts to limit freedom of navigation in the strategic waters, where Chinese, Japanese and some Southeast Asian navies operate, according to Reuters.