Billionaire investor Charlie Munger told CNBC on Monday that he wished Berkshire Hathaway had bought even more Apple stock.

"I think we've been a little too restrained," Munger told on CNBC's "Squawk Box" from Omaha, Nebraska. "I wish we owned more of it."

On Friday, Buffett revealed that Berkshire Hathaway bought 75 million shares of the tech giant during the first quarter. That adds to the 165.3 million shares Berkshire already owned at the end of 2017.

When asked whether he thought Berkshire's current holdings of Apple's stock was enough, Munger simply said, "No."

Munger, who said he does not own an iPhone, said the U.S. tech giant is "reasonably priced," strong and has a smart management team under CEO Tim Cook. "That's a very desirable combination," he added.

Warren Buffett and his longtime investing partner and vice chairman, Munger, spoke to the tens of thousands of attendees at their annual meeting on a wide range of topics from their massive stake in Apple to missing out Google and Amazon to bashing as "rat poison."

Berkshire first made an investment in Apple in 2016 after a person at the company bought about 10 million shares. Buffett then looked at the stock and purchased considerably more, the billionaire recalled in August to CNBC.

Apple stock was slightly higher in premarket trading on Monday. Last week, the stock posted its best week since 2011 after Buffett revelation that his firm bought more shares.

— Munger joins "Squawk Box" for three hours, 6 a.m. ET to 9 a.m. ET, with special guests Buffett and Microsoft co-founder and philanthropist Bill Gates.