With persistently low interest rates around the globe, billionaire investor Warren Buffett told CNBC on Monday he'd consider taking money out of banks, especially if negative interest rates result in customers being charged to park their money in accounts.

"There could be a point where you'd really want to start withdrawing currency," Buffett said in a wide-ranging "Squawk Box" interview from Omaha, Nebraska, after he hosted the annual meeting of Berkshire Hathaway shareholders on Saturday.

"If currency in a bank is worth less than currency in your hands ... that could produce something in the way of behavior," he said. "It's a different world. If you have a lot of money in euros, as we do ... you're better off putting it under your mattress than in a bank."

The easy money policies from central banks around the world is a "fascinating movie to watch," Buffett said, stressing he does not try to make money off central bank rate moves.

He acknowledged, however, that the resulting low yield environment is a drag on Berkshire's earning power.

"We have close to $60 billion that's out invested at about a quarter of percent or less," the Berkshire chairman and CEO said. "One point on $60 billion is $600 million a year. If we were getting 3 or 4 percent on that money, that's a couple billion to us. You notice it."