Berkshire Hathaway CEO Warren Buffett warned in a new interview that cyber attacks are a threat on par with nuclear, biological, and chemical weapons.

In an exclusive interview with Yahoo Finance Editor-in-Chief Andy Serwer ahead of the 2019 Berkshire Hathaway (BRK-A, BRK-B) Annual Shareholders meeting, Buffett said one of his biggest concerns is the use of cyber attacks by individuals, terror groups, and nation states.

And while problems such as disinformation campaigns, like those run by the Russian government in the lead-up to the 2016 and 2018 U.S. elections, are real, the billionaire suggested they pale in comparison to a full-on cyber attack.

"Well, I think cyber poses real risks to humanity," Buffett said during the interview, after Serwer asked him about Russian trolls. "Forgetting about the problem of even misinformation."

Cyber attack fears

When asked about whether business executives can be president, Buffett said that he'd want someone who understands the biggest threats to the U.S.

"That we live in a world where people, organizations, and occasionally countries could have people that would like to wipe out a large percentage of the American people, or maybe other countries, as well," Buffett said. "And that you now have capabilities — which I always thought, until recently, might classify it as nuclear, chemical, and biological — but I think you have to add cyber now."

The conversation was part of a wide-ranging interview that touched on topics including college, the newspaper business, and general investing advice.

Cyber attacks by nation states like Russia, Iran, China and other adversarial countries are on the rise, with China among the most prolific. Russia is probably best known for its hacking of the Democratic National Committee in the lead-up to the 2016 elections and its role in an ongoing disinformation campaign designed to sow discord in the U.S. and western democracies.

China, however, has ratcheted up its weaponization of cyberspace and has increased its attacks on the U.S.

This isn't the first time Buffett has brought up the specter of a major disaster caused by a cyber attack. During Berkshire's 2018 shareholders meeting, the CEO expressed his concern about such an incident.

"This is uncharted territory and it’s going to get worse, not better. You’re right in pointing that out as a very material risk that didn’t exist 10 to 15 years ago, and will get more intense as time goes on,” Buffett said, replying to a question about how he prepares for a big cyber-related disaster.

At the time, the Berkshire CEO said that there's a 2% chance of a $400 billion disaster occuring at some point each year as a result of some form of cyber attack.