U.S. consumer confidence index rose in May, following a modest decline in April after a downward revision, a New York-based business research group reported on Tuesday.

The index now stands at 128.0, up from 125.6 in April. The present conditions measure rose from 157.5 in April to 161.7 in May, the highest since March 2001, while consumer expectations gauge improved from 104.3 to 105.6, according to the latest report released by the Conference Board.

"Overall, confidence levels remain at historically strong levels and should continue to support solid consumer spending in the near-term," said Lynn Franco, Director of Economic Indicators at the Conference Board.

Meanwhile, the improvement in short-term expectations was modest, "suggesting that the pace of growth over the coming months is not likely to gain any significant momentum," the analyst noted in the report.

The consumer confidence index measures U.S. sentiment on current economic conditions and expectations for the next six months. Consumer spending accounts for about 70 percent of U.S. economic activity, drawing economists' attention to the numbers.