Investor Warren Buffett told thousands of Berkshire Hathaway shareholders on Saturday that the United States should not use “trade as a weapon” and anger the rest of the world like US President Donald Trump has done with his tariffs that roiled global markets.

“It’s a big mistake in my view when you have 7.5 billion people who don’t like you very well, and you have 300 million who are crowing about how they have done,” Buffett said as he addressed the topic on everyone’s mind at the start of the shareholders meeting.

While Buffett said it is best for trade to be balanced between countries, he does not think Trump is going about it the right way with his widespread tariffs. He said the world will be safer if more countries are prosperous.

“We should be looking to trade with the rest of the world. We should do what we do best and they should do what they do best,” he said.

America has been going through revolutionary changes ever since its birth and the promise of equality for all, which was not fulfilled until years later, Buffett said. But nothing that is going on today has changed his long-term optimism about the country.

“If I were being born today, I would just keep negotiating in the womb until they said, ‘You could be in the United States,’” Buffett said.