Warren Buffett, the chairman of Berkshire Hathaway and one of the most celebrated investors of the past few decades, penned an opinion piece in the New York Times in which he urged people to buy American stocks.

In the op-ed piece, titled “Buy American. I Am.” Buffett said that “over the long term, the stock market news will be good,” and asserts that “fears regarding the long-term prosperity of the nation’s many sound companies make no sense. These businesses will indeed suffer earnings hiccups, as they always have. But most major companies will be setting new profit records 5, 10 and 20 years from now.”

He revealed that “if prices keep looking attractive, my non-Berkshire net worth will soon be 100% in United States equities.”

Buffett used the examples of the Great Depression and the early 1980s, in which markets fell precipitously but then stormed back higher, to back up his assertion that “bad news is an investor’s best friend. It lets you buy a slice of America’s future at a marked-down price.”

He also said that “Today, people who hold cash equivalents feel comfortable. They shouldn’t. They have opted for a terrible long-term asset, one that pays virtually nothing and is certain to depreciate in value. Indeed, the policies that government will follow in its efforts to alleviate the current crisis will probably prove inflationary and therefore accelerate declines in the real value of cash accounts.”

Buffett said that “I don’t like to opine on the stock market,” and “I have no idea what the market will do in the short term.” But he concluded with a note that both his money and his recommendations are to buy American stocks.

Buffett has been in the news a lot recently. He was named by both major-party presidential candidates, John McCain and Barack Obama, as a potential successor to Henry Paulson as Secretary of the Treasury.

Also, Buffett a few weeks ago took big stakes in both Goldman Sachs (GS) and General Electric (GE). In each case, he received preferred shares, as well as warrants allowing him to buy common stock at low prices.