BEIJING-Chinese defence minister Wei Fenghe criticised the United States on Sunday for its support for self-ruled Taiwan and for naval operations in the disputed South China Sea, but said conflict or war between the two countries would be a disaster.

Wei told the Shangri-La Dialogue in Singapore, Asia’s premier defence summit, that China would “fight to the end” if anyone tried to split China from Taiwan, which Beijing considers a sacred territory to be taken by force if necessary.

“No attempts to split China will succeed. Any interference in the Taiwan question is doomed to failure,” said Wei.

He added: “If anyone dares to split Taiwan from China, the Chinese military has no choice but to fight at all costs ... The US is indivisible, and so is China. China must be, and will be, reunified.”

But he said both sides realised that any war between the two “would bring disaster to both countries and the world”. “We will strive for the process of peaceful reunification with utmost sincerity and greatest efforts but we make no promise to renounce the use of force.”

China-US ties have become increasingly strained due to a bitter trade war and US support for Taiwan and China’s muscular military posture in the South China Sea, where the US is also conducting freedom-of-navigation patrols.

On Saturday, acting US defence secretary Patrick Shanahan told the meeting that the US would no longer “tiptoe” around Chinese behaviour in Asia.

Wei, in a clear reference to the US said: “Some countries from outside the region come to the South China Sea to flex muscles in the name of freedom of navigation.”

In a combative speech, Wei said China would “fight to the end” if the United States wanted to fight on trade issues. But if Washington wanted to talk, “we will keep the door open”.

Chinese vice commerce minister Wang Shouwen said on Sunday that it would be impossible for the United States to use external pressure to force a trade agreement, and that it was irresponsible of Washington to accuse Beijing of backtracking.

Wang, speaking at a news conference, also declined to comment on whether President Xi Jinping will meet US president Donald Trump at this month’s G20 summit in Japan, saying he didn’t have that information.

Washington and Beijing have been vying for influence in the Asia-Pacific region, which hosts potential flashpoints such as the South China Sea, the Korean Peninsula and the Taiwan Strait.

Washington has been pushing back against Beijing’s aggressive militarisation of the South China Sea, where China has staked “indisputable” ownership over almost the whole area and rejects partial claims by Taiwan, Brunei, Malaysia, the Philippines and Vietnam.

Beijing is also regularly angered by US and other warships transiting through the Taiwan Strait, which it considers part of its territorial waters.