The U.S. Navy has sailed a warship through the Taiwan Strait, a move that came the same day that Beijing warned it would not rule out using force against self-ruled and democratic Taiwan to halt any move toward formal independence.

The “USS Antietam conducted a routine Taiwan Strait transit July 24-25 … in accordance with international law,” Cmdr. Clay Doss, a spokesman for the U.S. Navy’s 7th Fleet, told The Japan Times in a statement Thursday.

“The ships’ transit through the Taiwan Strait demonstrates the U.S. commitment to a free and open Indo-Pacific,” he said. “The U.S. Navy will continue to fly, sail and operate anywhere international law allows.”

The U.S. has ramped up the frequency of its transits of the Taiwan Strait, sending navy warships and coast guard vessels through the strategic waterway several times this year, much to the chagrin of Beijing.

In China’s defense white paper released Wednesday, Beijing said it will not renounce the use of force in efforts to reunify Taiwan with the mainland, noting that its armed forces are bolstering their military preparedness for such a contingency.

“The PLA will resolutely defeat anyone attempting to separate Taiwan from China and safeguard national unity at all costs,” the paper said.

Speaking at a news conference on the paper’s release, Defense Ministry spokesman Wu Qian said the threat of Taiwan separatism is growing and warned that those who are seeking independence will meet a dead end.

“If anyone dares to separate Taiwan from China, the Chinese military will certainly fight, resolutely defending the country’s sovereign unity and territorial integrity,” Wu said.

Taiwan, a democratically governed island, split from Communist Party-ruled mainland China after the civil war ended in 1949. Beijing views Taiwan as a renegade province that must be brought back into the fold — by force if necessary.

Earlier this month, the U.S. State Department approved a possible $2.2 billion arms package requested by Taiwan that includes 108 General Dynamics Corp. M1A2T Abrams tanks and 250 Stinger missiles, among other weapons.

The move stoked China’s ire and prompted it to threaten sanctions against the U.S.

“China resolutely opposes the wrong practices and provocative activities of the U.S. side regarding arms sales to Taiwan,” the paper said.

The U.S. has no formal ties with Taipei but is bound by the Taiwan Relations Act to help it defend itself, and Washington is the island’s main source of arms. The Pentagon said Washington has sold Taipei more than $15 billion in weaponry since 2010.

Taiwan’s Defense Ministry said it made the request in light of an increasing military threat from China.

Beijing has called Taiwan “the most important and sensitive issue in China-U.S. relations” and has bolstered its military presence near the island, sailing its sole operating aircraft carrier through the Taiwan Strait in January and March of last year and holding large-scale “encirclement” exercises and bomber training throughout last year and into this year.

In an editorial published late Wednesday, China’s hawkish, state-run Global Times newspaper said that “the risks posed by the Taiwan secessionist forces and the increasingly clear U.S. intention to contain China,” are prompting the Chinese military to “develop the ability to withstand the potential U.S. military extortions under extreme circumstances.”

“There are few possibilities and necessities for China to possess military power to provoke the U.S.,” the editorial said. “But if attacked by the U.S., China must be able to cause unbearable losses to the U.S.”

It said that military parity between the two powers “in this sense is gradually being established.”

“Especially in the Taiwan Straits, China’s military confidence is multiplying daily,” the editorial added. “The mainland’s military pressure against Taiwan has become an increasingly effective lever to prevent Taiwan secessionist forces. It has become difficult for the U.S. to weaken China’s leverage.”