Taipei (dpa) - The US Navy said it sailed a warship through the strategic Taiwan Strait on Wednesday and Thursday, less than a day after China said it would "not renounce the use of force" in its plan to reunite with Taiwan.

Clay Doss, spokesman for the US Navy's Seventh Fleet, said that the operation, conducted by USS Antietam, was routine and "in accordance with international law."

He added that the transit "demonstrates the US commitment to a free and open Indo-Pacific," adding that "the US Navy will continue to fly, sail and operate anywhere international law allows."

Taiwan's Defence Ministry confirmed that it had monitored the passage and the situation was nothing unusual.

It was the sixth time this year US Navy vessels have sailed through the 180-kilometre-wide Strait, which separates Taiwan from China.

The move came hours after Beijing released a defence white paper which stated that Taiwan's "complete reunification" with China was in China's fundamental interests.

"China must be and will be reunited," Wednesday's paper said. "We make no promise to renounce the use of force, and reserve the option of taking all necessary measures."

Taiwan, a self-governed democracy that China sees as a renegade province, condemned Beijing for refusing to renounce the use of force.

On Thursday President Tsai Ing-wen said Taiwan needed to strengthen its defences and maintain international cooperation.

"All parties share responsibilities for cross-strait peace and regional stability. China has its responsibility. ... We've done our best for a long time," Tsai told reporters.

Tensions between Washington and Beijing over their trade spat have been exacerbated recently by the US stance on Taiwan.

Earlier this month Tsai became the first sitting Taiwanese president to host a public event at a venue belonging to Taiwan’s representative office to the US, while Washington also approved the potential sale of 2.2 billion dollars worth of arms to Taiwan despite Chinese opposition.