Continued fears about a potential United States sanction against Iran kept the oil rally going strong on Tuesday, sending prices higher for the sixth straight day. Brent crude futures surpassed $75 per barrel briefly during the Asian morning session, to a high of $75.20 before falling slightly. As of 1:02 p.m. HK/SIN Brent crude futures were trading at $74.89 per barrel. Brent is now up over 20 percent since February.

U.S. WTI futures were trading at $68.89 per barrel, down ten cents per barrel from their session highs but still up 0.36 percent since yesterday. The U.S. has until May 12th to confirm whether it will be withdrawing from the Iran nuclear deal. A withdrawal would likely bring additional sanctions against Iran and could push oil prices up as much as $5 per barrel, according to Stephen Innes, head of Asia/Pacific trading at OANDA.

U.S. sanctions have recently been driving other commodity prices as well. The announcement of U.S. sanctions against Russian aluminum manufacturer Rusal sent aluminum prices soaring in to 2011 highs as traders worried about supply. Yesterday the U.S. Treasury Department extended the sanction date from June to October, sending aluminum prices broadly lower. The White House also said that it would consider lifting the sanctions entirely if Rusal’s major shareholder, Oleg Deripaska, gave up control of the company. Deripaska owns 48 percent of the company and his shareholder agreement allows for control of the company. Aluminum prices on the London Metal Exchange plummeted nearly 9 percent after the sanction extension, the steepest one-day drop in eight years.