For the second time this month, US warships on Thursday sailed through the sensitive Taiwan Strait, prompting China to denounce the “provocative actions.”

The United States said guided-missile destroyers USS John S. McCain and USS Curtis Wilbur conducted a routine transit through the strait between eastern Nationalist China and the democratically run island of Taiwan that China views as a rouge province.

“The ship’s transit through the Taiwan Strait demonstrates the US commitment to a free and open Indo-Pacific,” the US Navy’s 7th Fleet said in a statement. “The United States military will continue to fly, sail and operate wherever international law allows.”

Taiwan’s Ministry of Defense confirmed the trip, saying in a statement that the U.S. ships traveled north through the strait from the South China Sea on Thursday morning.

It is the second time the 7th Fleet has sent vessels down the strait this month after the USS Mustin made the trip on December 19.

Chinese Defense Ministry spokesperson Senior Col. Wu Qian accused the United States of attempting to “flex muscles and stir up troubles.”

In the statement, Wu said the United States was sending “erroneous signals to the ‘Taiwan Independence’ forces and severely jeopardized peace and stability across the Taiwan Strait.”

Naval and air forces were deployed to conduct tracking and monitoring of the two US destroyers, Wu said, stressing that the People’s Liberation Army is on high alert and is “ready to respond to any threats and provocations” to safeguard China’s sovereignty. SOVEREIGNPH