Oil futures ended higher on Tuesday, getting a boost as economic data from China hinted at better prospects for energy demand. Meanwhile, discussions in Vienna aimed at bringing the U.S. back into a nuclear deal with Iran appeared to make little progress. The White House said it expects a “long process” to reach an agreement. The U.S. and Iran aren't meeting directly and representatives from European and other nations are serving as go-betweens instead. Through those intermediaries, the U.S. and Iran agreed to establish two working groups to try to get both countries back into compliance with the 2015 Iran nuclear deal, The New York Times reported Tuesday. West Texas Intermediate crude for May delivery rose 68 cents, or 1.2%, to settle at $59.33 a barrel on the New York Mercantile Exchange.