According to retired US Army lieutenant general H.R. McMaster, China is preparing its military for war over Taiwan.
Relations between mainland China and Taiwan have long been strained over the island's push for independence, but have grown even more tense amid an increasingly aggressive Beijing.
Amid growing tensions, McMaster said he believes China could be gearing up for military action to take control of the island nation during an appearance on CBS News' Face the Nation on Sunday—adding that Chinese President Xi Jinping, who secured a historic third term last year, has made it clear he plans to retake Taiwan.
"Xi Jinping has made it quite clear, in his statements, that he is going to make, from his perspective, China whole again by subsuming Taiwan," McMaster said. "And preparations are underway."
McMaster said the best way to prevent a widescale military war over Taiwan is "deterrence," adding that the United States, which already spends more than $1.6 trillion on defense, should invest even more in national security because it would be "much more costly" to respond to a war with China, which boasts one of the strongest militaries across the globe and continues to seek to grow its influence in the Pacific region.
"China has become increasingly aggressive, not only from an economic and financial perspective and a wolf warrior diplomacy perspective, but physically, with its military," the former national security adviser said. "And what's really disturbing is, I think, Xi Jinping is preparing the Chinese people for war."
He pointed to some of Xi's speeches, which have taken on a hardline tone in recent months, as evidence that the U.S. should take the threat of war more seriously and "extend our power." Doing so would also compel allies to invest more in their national defense, which would further serve as a deterrent, he added.
He said the U.S. and its allies need to "be careful not to mirror image" or "fall into the same traps" they did with Russia, which launched an invasion of Ukraine last February.
McMaster's warning follows other indications that China may be considering a war over Taiwan. In November, The Guardian reported that Xi told his military to "focus all its energy on fighting" to prepare for a potential war.
"Focus all [your] energy on fighting, work hard on fighting and improve [your] capability to win," he reportedly said.
China-Taiwan relations flared last August after House Speaker Nancy Pelosi made a historic visit to Taiwan. At the time, Beijing made several threats against her visit and launched military drills around the island, leading to concerns that the conflict could escalate.
