Twitter’s new owner certainly knows how to get people’s attention. 

Elon Musk, whose offer to buyout the company for an approximate $44 billion was accepted last month, was busy tweeting over the weekend—with two comments in particular that have raised some eyebrows. In one tweet sent out on Saturday, Musk replied to a news story about Japan’s population falling by 644,000 to 125.5 million in 2021, and shared with his followers that he believes “Japan will eventually cease to exist.”

“At risk of stating the obvious, unless something changes to cause the birth rate to exceed the death rate, Japan will eventually cease to exist,” Musk wrote. “This would be a great loss for the world.”

Japan, which saw its population peak in 2008, has the world’s third-largest economy, and the government has attempted to address the country’s low birthrate in recent years, despite the population’s 11th consecutive year of decline, per The Guardian.

“What is even the point of tweeting this,” wrote Tobias Harris, senior fellow at the Center for American Progress. “The anxieties surrounding Japan’s demographic future is not that ‘Japan will eventually cease to exist’ but rather the profound social dislocations that are occurring as a result of the decline to a lower population level.”

On Sunday, Musk decided to tweet something a little more cryptic, writing, “If I die under mysterious circumstances, it’s been nice knowin ya.”

While it remains unclear exactly why he decided to tweet this at 9 p.m. on a weekend, it appears to be in response to a message he posted from Dmitry Rogozin, the former deputy Russian prime minister in charge of Russia’s space agency. In the message, Rogozin writes that Musk will “be held accountable like an adult – no matter how much you’ll play the fool,” and accuses the Tesla CEO of being “involved in supplying the fascist forces in Ukraine with military communication equipment.”

“From the testimony of the captured commander of the 35th Marine Brigade of the Armed Forces of Ukraine, Colonel Dmitry Kormyankov, it turns out that the internet terminals of Elon Musk’s Starlink satellite company were delivered to the militants of the Nazi Azov Battalion and the Ukrainian Marines in Mariupol by military helicopters,” Rogozin wrote, per Musk’s translation. 

Musk hit back with the line, “the word ‘Nazi’ doesn’t mean what he seems to think it does.”