BEIJING (AP) — China accused the U.S. of staging a show of force by sailing two Navy warships through the Taiwan Strait on Thursday morning.

The Navy said the Arleigh Burke-class guided missile destroyers USS John S. McCain and USS Curtis Wilbur “conducted a routine Taiwan Strait transit” in accordance with international law.

Their movement “demonstrates the U.S. commitment to a free and open Indo-Pacific,” the Navy said in a statement on its website.

China’s Defense Ministry called the move a “show of force” and a provocation that “sent the wrong signal to the ‘Taiwan independence forces’ and seriously endangered peace and stability in the Taiwan Strait area.”

“We firmly oppose this," the ministry said in a statement on its official microblog, adding that it monitored the ships' passage from the air and sea. “The Chinese People’s Liberation Army at all times maintains a high level of alert and can respond at any time to any threat or provocation and resolutely defend national sovereignty and territorial integrity."

While China claims Taiwan as its own territory, the busy Taiwan Strait is generally considered an international waterway. China fiercely opposes any signal of U.S. military support for Taiwan, a self-governing republic that relies on Washington for defensive weapons and political backing in the face of Chinese threats to annex the island by force.

Taiwan's Defense Ministry issued a statement saying it had observed the passage of the ships passage and that “the situation is normal."