The possibility of the U.S. economy sliding back to recession is very small despite the fragile economic recovery, U.S. billionaire investor Warren Buffett said here on Tuesday.

The U.S. economy would not slip back to recession unless events in Europe get out of control and the spillover effects hit the world's largest economy, Buffett said at an event hosted by the Economic Club of Washington.

The chairman and CEO of Berkshire Hathaway Inc. called the ongoing eurozone debt crisis the "big question" for the global economy, quoting former U.S. President Abraham Lincoln as saying that a house divided against itself cannot stand.

However, Buffett stressed that the United States must make its fiscal house in order by increasing tax revenue and slashing spending, adding that he supports raising income tax and capital gains tax rates to balance the federal government's budget.

Buffett has famously said that he paid at a lower tax rate than his secretary. The Obama administration has been touting the importance of so-called "Buffett Rule" that millionaires should share the burden of mounting government fiscal pressure.

Nearly one-quarter of all U.S. millionaires pay a lower tax rate than millions of middle-income taxpayers currently, figures from the White House showed.

On the spending side, the U.S. federal government has registered a budget deficit surpassing 1 trillion U.S. dollars for three consecutive years.