U.S. stocks closed mixed Thursday, as the S&P 500 closed at an all-time high. In U.S. economic news, the government said that first-time claims for unemployment benefits fell last week. All eyes will be on the jobs report for February that will be released Friday. Economists surveyed expect that 150,000 jobs were added last month and that the unemployment rate remained steady at 6.6 percent. In international economic news, investors are confident, for now, that the conflict will not escalate into a full-blown war. But the crisis could have unpredictable political ramifications. Political leaders in Crimea have called for a referendum this month on whether to remain part of Ukraine or join the Russian Federation. Meanwhile, U.S. and European officials unveiled new sanctions aimed at pressuring the Russians and Ukrainians deemed responsible for the crisis. In corporate news, Staples shares plunged after the office supplier reported a slump in last year's sales and announced that 225 stores will be closed by the middle of 2015. Costco fell after the warehouse retailer reported sales and profits that missed forecasts. Pandora shares sank nearly 6 percent after the online radio service said listener hours fell to 1.51 billion in February from 1.58 billion in January. It also decided to stop issuing monthly reports on user growth. The pullback came after Pandora shares hit an all-time high earlier this week. Even with Thursday's decline, the stock is still up nearly 40 percent this year. The dollar gained ground against the euro, the pound, and the yen. Light sweet crude oil for April delivery added 11 cents to $101.56 a barrel on the New York Mercantile Exchange. Gold futures moved up $11.50 to $1,351.80 an ounce. The Dow Jones industrial average rose 61.71, or 0.38 percent, to 16,421.89. The broader Standard & Poor's 500 index climbed 3.22, or 0.17 percent, to 1,877.03. The technology-heavy Nasdaq composite index declined 5.84, or 0.13 percent, to 4,352.13.