Speaking via teleconference at Los Angeles’s All-In Summit this week, Musk said he believed he had “a pretty good understanding, as an outsider, of China.”

“I understand China well, I’ve been there many times, have met with senior leadership at many levels, and Tesla has been very successful domestically in China,” he said, before describing Taiwan as a “fundamental thing” of importance to lawmakers in Beijing.  

Musk compared the link between China and Taiwan to Hawaii’s relationship with the United States—that is, that Taiwan is “an integral part of China that is arbitrarily not part of China.”

“Really I think it’s getting to the point increasingly year over year where China’s military strength is increasing and [America’s] is more or less standing,” he said, implying that it was likely China would use force to bring Taiwan under its control.

Last year, President Joe Biden said U.S. forces would defend Taiwan in the event of a Chinese invasion—sparking fury from China.

However, Musk suggested at the All-In Summit that this was probably an unfeasible task.

“Strategically you can imagine trying to defend Taiwan is not easy because it’s very close to the coast of China,” he argued.

Self-ruled Taiwan—an island about 100 miles off of the southeast Chinese coast—is seen by Beijing as a rebel province that must be brought back under the mainland’s control.

Tensions around Taiwan’s status have been rising steadily in recent years, with Western speculation that Beijing could invade the island gathering speed.

In a post on X—Musk’s own social media platform—Taiwan’s foreign minister Joseph Wu lashed out at the Tesla CEO’s take on the situation.

Wu said he was hopeful Musk would convince the ruling Chinese Communist Party to make X, formerly Twitter, accessible on Chinese soil, where it is currently banned.

“Perhaps he thinks banning it is a good policy, like turning off Starlink to thwart Ukraine’s counterstrike against Russia,” Wu said in the post, which was published via the Taiwanese Ministry of Foreign Affairs’s account.

“Listen up, Taiwan is not part of [China] and certainly not for sale!” he added.

Hope @elonmusk can also ask the #CCP to open @X to its people. Perhaps he thinks banning it is a good policy, like turning off @Starlink to thwart #Ukraine’s counterstrike against #Russia. Listen up, #Taiwan is not part of the #PRC & certainly not for sale! JW https://t.co/HEhyTYYXFp

— 外交部 Ministry of Foreign Affairs, ROC (Taiwan) 🇹🇼 (@MOFA_Taiwan) September 13, 2023

Representatives for Musk were not available when contacted by Fortune.

Taiwan, which has grown into a major Asian economy, is home to semiconductor giant TSMC, and a huge amount of the world’s electronics are powered by chips manufactured on the island.

Although Taiwan has been self-governed for more than seven decades, it is not recognized by the U.N. as a nation in its own right, with the organization regarding Beijing as the island’s diplomatic representative. China insists there is only “one China”—and that Taiwan is part of it.

China, officially the People’s Republic of China (PRC), has vowed to “unify” Taiwan with the mainland, using force if necessary, and in recent years has taken increasingly aggressive action to demonstrate the seriousness of that objective.

For example, Taiwan has reported numerous occasions of Chinese military aircraft flying into its air defense zone, while China carried out military exercises including the firing of ballistic missiles near the island last year.  

Tensions have increased in recent years as the U.S. government has demonstrated support for Taiwan, with former House Speaker Nancy Pelosi visiting the island in 2022, and Taiwanese president Tsai Ing-wen making an official visit to the U.S. earlier this year.

Musk’s comments on Taiwan and China come as the SpaceX CEO and world’s richest person continues to make headlines over his decision to refuse the Ukrainian military access his Starlink satellite service for a counteroffensive in Russian-occupied Crimea.

“At no point did I or anyone at SpaceX promise coverage over Crimea,” he said in a post on X last week. “Moreover, our terms of service clearly prohibit Starlink for offensive military action, as we are a civilian system, so they were again asking for something that was expressly prohibited.”