SAN FRANCISCO — The U.S. economy has flatlined and its growth has tempered even with signs of a recovery in residential housing, billionaire investor Warren Buffett said Thursday.

In the past two months, there has been a discernible pickup in housing, albeit from a low base, the chairman of Berkshire Hathaway told cable network CNBC.

"The rest of the economy is slowing. It's not heading downward, but it is not growing at a rate it was earlier," he added.

The comments are in line with manufacturing and unemployment data from June that pointed to a weaker trend.

Still, Buffett thinks the U.S. economy is doing better than most other large economies in the world, and reiterated that housing would be the key to its sustained recovery.

"The little pickup in housing is not enough to offset what's going on in the world generally," he added.

Even so, there isn't much more the Federal Reserve can do to prop up the economy when banks are sitting on tons of money and interest rates are technically negative, according to Buffett.

The minutes of the Federal Reserve's policy meeting last month, released Wednesday, showed that only four Fed officials specifically mentioned more quantitative easing in their forecasts, while several others said more action could be warranted if economic conditions deteriorated.

Buffett also blamed part of the economic woes on Congress and urged politicians to stop squabbling.

"People have a feeling that Congress is inept and sort of paralyzed by the desire of each side to make the other side look bad," he said. "That has got to be a factor in general confidence."

Buffett noted that Europe has taken a turn for the worse, particularly in the past month. "Things have slipped pretty fast," he said.