On the economic front, consumer spending fell 0.2 percent in April for the first time in almost a year, according to the Commerce Department, disappointing economists who had expected a gain of 0.1 percent. And inflation pressures remained subdued, rising just 0.7 percent in the last 12 months, the smallest increase since October 2009.
The weak spending and the lack of inflation pressures could dampen market speculation the U.S. central bank might start scaling back monetary easing later this year.
"All eyes remain on the U.S., analyzing every piece of data to establish if, and when, stimulus measures will be withdrawn—with every piece of bad news being actively welcomed by the market," wrote Rebecca O'Keeffe, head of investment at Interactive Investor, in a note. "This inverted logic is unsustainable in the long term, but for the moment, as the withdrawal of liquidity is perceived as being more painful than an economic slowdown, investors are happy to live in this bubble for as long as they can."
(Read More: Asia Stages Comeback on QE Assurance)
In corporate news, Dell shares edged lower on news that a special committee recommended that shareholders approve the bid from founder Michael Dell and Silver Lake to take the computer maker private.
Among earnings, Lions Gate rallied after the entertainment company topped earnings expectations, thanks to its box-office success of "The Hunger Games" and the company's acquisition last year of independent studio Summit Entertainment.
Krispy Kreme shares ripped higher after the doughnut maker easily topped earnings expectations and also raised its full-year guidance.
The Dow Jones Industrial Average and S&P 500 are both up over 3 percent this month. In comparison, the FTSEurofirst 300, a broad measure of European stocks, is higher by 2 percent. Asia's traditional market laggard, the Shanghai Composite gained 5 percent in May, outperforming Asia's other major markets.
(Read More: This Chart Shows Dow Should Be (a Lot!) Lower)
Also on the economic front, the Chicago PMI (Purchasing Managers' Index) for May will be released at 9:45 am ET, and will provide an early indication of how Monday's ISM manufacturing index might read. Economists polled by Reuters expect a reading of 50. And the University of Michigan will publish its final reading for consumer sentiment in May at 9:55 am ET. Economists polled by Reuters forecast the index will read 83.7, the same as in April.
Across the Atlantic, OPEC (Organization of Petroleum Exporting Countries) ministers met in Austria on Friday, and are expected to leave the output target at 30 million barrels per day. However, behind-the-scenes discussions indicated the group is concerned about the growing impact of U.S. shale oil on some of its members.
(Read More: Rising Oil Prices: The Euro Zone's Next Big Problem?)