Billionaire businessman Warren Buffett said while he favors free trade for the good it brings, wealthy nations should take care of people hurt by it.

"Free trade is wonderful for the world and for the United States, but its benefits are diffused among 320 million people," the Berkshire Hathaway CEO told CNBC on Monday. "You buy your bananas cheaper because we don't try and produce them in the United States. But the penalties from free trade are terrible to specific industries."

Moving an industry out of the country ends up putting Americans out of work, and it hurts people nearing retirement who have spent their whole lives training to do one thing and will not see a practical benefit from retraining as younger workers might.

"As an investor, I make a dumb decision on owning a shoe company, but if I own a good insurance company, I can diversify away the problems," he said. "If you are a 55-year-old steelworker, you can't diversify away your talents.

"A rich country that's prospering because of free trade . . . should keep the free trade as much as possible, but they should also take care of the people that become the roadkill when industries move," Buffett said. "A rich society should figure out a way to take care of those people."

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