U.S. stock-index futures were mostly lower on Tuesday, after data on home prices came in just above expectations.
Walgreen shares fell in early New York trading after the drugstore chain reported a 16 percent rise in its fiscal third-quarter earnings from the year-earlier period, but still missed expectations. Dean Foods declined after the Wall Street Journal cited unidentified sources in reporting Federal authorities had asked for information related to an insider-trading probe of investor Carl Icahn from the food-and-beverage supplier.
The Case-Shiller index of home prices rose 10.8 percent in April from the year earlier, and 1.1 percent from the prior month, just above estimates of a 1.0 percent rise.
The data comes an hour ahead of a new-home sales number for May, and comes a day after a report that had existing-home sales rising more than expected last month.
"We expect the improvement in home sales to remain on track even as mortgage rates start to creep up again later this year," said Paul Diggle of Capital Economics in a research note out late on Monday.
Also, the consumer confidence index for June will be released at 10 a.m.
Speaking in New York on Tuesday, Philadelphia Federal Reserve Bank President Charles Plosser said the economy is nearing the central bank's targets more quickly than expected, and could have the Fed increasing interest rates sooner than anticipated.
Other stocks to watch include Monsanto, after media reports that it is considering a takeover bid for Swiss agricultural firm Syngenta. A spokesperson for Syngenta declined to comment, telling CNBC that "rumors" were commonplace in the financial markets, particularly at present.
Abbott Laboratories confirmed late on Monday it had agreed to buy Russian drug maker Veropharm, despite the ongoing Russia-Ukraine sovereignty crisis.
After two months of heavy fighting, separatist leaders in eastern Ukraine have agreed to a ceasefire with government forces until June 27. The truce runs parallel to a military ceasefire declared by Ukrainian President Petro Poroshenko last Friday, as part of a plan to end the insurgency.
Secretary of State John Kerry was in Iraq's Kurdistan region on Tuesday, hoping to persuade leaders not to withdraw from the political process in Baghdad, after Kurdish forces seized control of the oil-rich city of Kirkuk.
Back in the U.S., the Treasury will auction $30 billion in during the afternoon.
—By CNBC's Katy Barnato