U.S. consumer confidence declined in March, falling below expectations and breaking a two-month streak of gains.

The Conference Board's measure of consumer attitudes on current and future economic conditions fell to 127.7, well below expectations of 131 from a survey of Reuters economists.

Consumer confidence fell in March after hitting an 18-year high in February, mostly due to outlook on business conditions.

Outlook was less optimistic about current business conditions, as well as their prospects in the next six months.

"Despite the modest retreat in confidence, index levels remain historically high and suggest further strong growth in the months ahead," said the Conference Board's director of economic indicators, Lynn Franco.

Consumer confidence in February reached its highest level since 2000, driven by the view of an improving labor force.

The index takes into account Americans' views of current economic conditions and their expectations for the next six months. Economists pay close attention to the numbers because consumer spending accounts for about 70 percent of U.S. economic activity.