Asian stocks closed lower, while European shares also declined on continued lack of resolution between Greece and its creditors. However, the ATHEX Composite turned higher later in the day.
Euro zone finance ministers meet in Luxembourg on Thursday to discuss a reforms-for-aid deal for Greece but expectations of a deal are low.
Greece is set to default on a 1.5 billion euro ($1.7 billion) debt repayment to the International Monetary Fund on June 30 unless it receives fresh funding from its creditors—the European Union, the International Monetary Fund and the European Central Bank.
IMF Managing Director Christine Lagarde said on Thursday in a Reuters report that there is no possibility of further delay in repayment after that date.
Read MoreGreece talks go down to the wire as Eurogroup meets
"Has the debate subtly moved on from trying to find agreement to what happens with no agreement? I think it has," Bill Blain, a strategist at Mint Partners, said in a note.
The dollar index—a measure of the dollar's value against a basket of other currencies—extended losses after earlier hitting a one-month low at 93.905 on what were perceived as dovish comments from Fed chief Janet Yellen following the end of Wednesday's two-day meeting.
Bond yields edged higher as traders digested economic data, with the U.S. 10-year Treasury yield near 2.32 after earlier falling below 2.3 percent. The 2-year yield traded near 0.65 percent, up from 0.64 percent earlier.
Earnings due this session include Kroger, Rite Aid, Red Hat, Finisar, Smith & Wesson.
Read More Early movers: RAD, LUV, CL, FIT, H, JBL, GM & more
In corporate news, Oracle reported adjusted quarterly profit of 78 cents per share, 8 cents below Street forecasts. Revenue also missed estimates, with the software maker hurt by a stronger dollar. It did, however, see sales growth in its cloud-based offerings.
Apple is generating sizable profits from sales of Apple Watch bands, according to data seen by Reuters. Many buyers of the watch are buying more than one band, according to data provided by research firm Slice Intelligence.
Southwest Airlines—Barclays downgraded the airline's stock to "underweight" from "overweight," saying the stock is now trading at too large a premium to its peers.
—CNBC's Peter Schacknow contributed to this report