Crude-oil futures continued to trade slightly higher on Friday as investors eyed ongoing political instability in Nigeria and as tension between the U.S. and Iran over Iran's nuclear proposals showed no sign of abating. April-dated light sweet crude was recently up 23 cents at $60.70 a barrel in electronic trade. The contract closed up 45 cents at $60.47 a barrel the previous day on Nymex, ending a three-day drop. "The market is extremely hesitant to go below $60 a barrel and that is because of the Nigerian outages for the most part," said Deborah White, a senior energy analyst at Societe Generale. She said that the lack of a diplomatic solution in Iran was also still helping to bolster the price of crude. Iran reportedly said Wednesday it could inflict "harm and pain" on the U.S. if Washington recommended that the United Nations tackle the Middle Eastern nation's nuclear issue. However, White said that the market is not expecting sanctions to effect oil exports. "The IEA has already defused that particular situation by simply saying that if exports were curtailed, then they would release strategic stocks," she said.