NEW YORK -- US billionaire investor Warren Buffett on Saturday warned against tariffs and protectionism.

"Trade should not be a weapon," the chairman and CEO of Berkshire Hathaway, Buffett, told the company's annual shareholders meeting, which was held in Omaha, Nebraska.

"It's a big mistake, in my view, when you have seven and a half billion people that don't like you very well, and you got 300 million that are crowing in some way about how well they've done -- I don't think it's right, and I don't think it's wise," said Buffett.

"I do think that the more prosperous the rest of the world becomes, it won't be at our expense, the more prosperous we'll become, and the safer we'll feel, and your children will feel someday," Buffett added.

Operating earnings of Berkshire Hathaway decreased by 14 percent to $9.64 billion in the first quarter of 2025, with over $700 million of loss related to foreign exchange.

"Our periodic operating results may be affected in future periods by impacts of ongoing macroeconomic and geopolitical events, as well as changes in industry or company-specific factors or events," Berkshire Hathaway said in its quarterly earnings report issued on Saturday.

"The pace of changes in these events, including international trade policies and tariffs, has accelerated in 2025. Considerable uncertainty remains as to the ultimate outcome of these events," said the company.