Warren Buffett: Berkshire's success has almost everything to do with being based in the US
"I know that a very large part of (our) success has come because we have been operating in the United States," he said.
"There's more to come. So join in with us. Berkshire Hathaway is going to do well in the years ahead."
In a video address to the SelectUSA summit, aimed at attracting foreign investment, Buffett said U.S. advantages included rule of law, equality of opportunity and encouragement for innovators.
Buffett's latest endorsement of the merits of investing in the US shouldn't come as a complete surprise to investors, however.
In his most recent annual letter to shareholders, Buffett said that the "Mother Lode" of opportunities runs through America. Buffett added that, "The treasures that have been uncovered up to now are dwarfed by those still untapped," and also asked, "Indeed, who has ever benefited during the past 238 years by betting against America?"
In 2014, Buffett said that Berkshire and its subsidiaries spent a combined $15 billion on plant and equipment, with 90% of this happening in the US.
Reuters noted, however, that Buffett has invested quite a bit of money abroad, especially for someone who talks up America so frequently.
But as Buffett wrote in his annual letter, his bullishness on America may just come down to a little bit of personal bias.
"Through dumb luck, Charlie and I were born in the United States," Buffett said, "and we are forever grateful for the staggering advantages this accident of birth has given us."
(Reporting by Krista Hughes; Editing by Jonathan Oatis)