In the latest example of escalating tensions between China and Taiwan, the two countries have spent days sparring over the Taiwan Strait. On Tuesday, Taiwan’s foreign ministry expressed support for the travel of international vessels, including those from the United States, through the strait.

“The Taiwan Strait is international waters, and the waters outside our territorial waters are subject to the ‘freedom of the high seas’ principle of international law,” Taiwan Foreign Ministry spokesperson Joanne Ou told reporters. “We understand and support the U.S. freedom of navigation missions’ contribution to promoting regional peace and stability.”

Ou’s remarks were in response to comments made Monday by China Foreign Ministry spokesperson Wang Wenbin regarding the Taiwan Strait. Wenbin said China “has sovereignty, sovereign rights and jurisdiction” over the strait.

“The biggest threat to the peace and stability across the Taiwan Strait does not come from elsewhere but the obdurate separatist activities of the ‘Taiwan independence’ forces and the U.S.’ connivance and endorsement of such activities,” Wenbin said. “Since the beginning of this year, the U.S. naval ships have transited the Taiwan Strait once a month on average. U.S. military aircraft have engaged in large-scope, frequent and provocative close-in reconnaissance to deter and pressure China.”

The back and forth between China and Taiwan over the Taiwan Strait came just two days after Defense Secretary Lloyd Austin gave a new warning on China’s role in the ongoing tensions. Austin was speaking at the annual Shangri-La Dialogue in Singapore, a country that recently signed a trade deal with the U.S. to counter China’s influence in the Indo-Pacific region.

“We’ve witnessed a steady increase in provocative and destabilizing military activity near Taiwan and that includes [Chinese military] aircraft flying near Taiwan in record numbers in recent months and nearly on a daily basis,” Austin said Saturday. “We remain focused on maintaining peace, stability and the status quo across the Taiwan Strait. But [China’s] moves threaten to undermine security and stability and prosperity in the Indo-Pacific.”

Reuters contributed to this report.