Wei said the People's Liberation Army would not "yield a single inch of the country's sacred land." China's ruling Communist Party maintains that Taiwan is part of China, and has used increasingly aggressive rhetoric toward the democratic island, which split from the mainland amid a civil war 70 years ago. It opposes Taiwan's independence and formally says it seeks a "peaceful reunification" while refusing to rule out the use of force if necessary to achieve that goal.
"The PLA has no intention to cause anybody trouble but it is not afraid to face up to troubles. Should anybody risk crossing the bottom line, the PLA will resolutely take action and defeat all enemies," Wei said.
Relations between Beijing and Taipei have deteriorated since Taiwan elected a pro-independence president, Tsai Ing-wen, in 2016. China has since increased diplomatic pressure, cut off its contacts with the island's government and discouraged travel there by Chinese tourists.
"China must be and will be reunified. We find no excuse not to do so. If anyone dares to split Taiwan from China, the Chinese military has no choice but to fight at all costs, at all costs, for national unity," Wei stressed.
"We will strive for the prospect of peaceful unification with utmost sincerity and greatest efforts, but we make no promise to renounce the use of force." Wei was addressing defense chiefs, officials and academics at the Shangri-La Dialogue in Singapore.
U.S. Acting Defense Secretary Patrick Shanahan, who spoke to the same gathering on Saturday, was not present at Wei's speech. Shanahan called China's efforts to steal technology from other nations and militarize man-made outposts in the South China Sea a "toolkit of coercion" and urged it to stop activities the U.S. perceives as hostile.
China is pitted against smaller Southeast Asian neighbors in multiple disputes over island reefs, corals and lagoons in the South China Sea, where it constructed seven outposts equipped with airstrips, radar and missile stations that Shanahan said Saturday could become "tollbooths" in one of the world's busiest waterways.
Beijing is currently firming up a pact with four rival claimants, containing norms and rules aimed at preventing a shooting war in the disputed waters. On Thursday, China's Defense Ministry dismissed a report that Australian navy pilots were hit by lasers earlier in May while exercising in the waters claimed by China. And on Sunday, Beijing closed off an area near Paracel Islands, which is also claimed by Vietnam and Taiwan, for military training exercises.
Wei said China built "limited defense facilities" but much of it was aimed at improving services and infrastructure for people living there. "It is only when there are threats would there be defenses. In face of heavily armed warships and military aircraft, how can we not deploy any defense facilities?" he said.
Most of the islands are uninhabited and have been used by fishermen from all sides to shelter during storms. Wei and Shanahan met on the sidelines of the conference Friday and agreed to improve communication and deepen exchanges and cooperation between their militaries.
On Sunday, Wei said the countries recognize that a conflict or war between them would have wide-reaching effects. "It takes two to cooperate but only one to start a fight," he said. "We hope that the U.S. side will work with us towards the same goal, follow the principles of non-conflict, non-confrontation, mutual respect and win-win cooperation, and steer the China-US relations in the right direction."
China last sent a high-ranking general to the conference in 2011. Its officials have been quick to downplay this as a mere coincidence, given the busy schedules of their higher-ups. But some observers see Wei's presence this time as a pointed attempt by China to cement its relationships in the region amid a trade war with the U.S. and having its businesses targeted with sanctions.