Oil prices slid on Tuesday as the dollar remained near a four-month high, but worries that U.S. President Donald Trump will pull out of the Iran nuclear deal underpinned the market.
U.S. West Texas Intermediate crude for June delivery finished Tuesday's session down $1.32 a barrel, or 1.9 percent, at $67.25, after settling up 47 cents on Monday.
London Brent crude for new July delivery was down $1.46, or 2 percent, at $73.23 a barrel by 2:28 p.m. ET. The June contract expired on Monday, settling up 53 cents at $75.17.
The U.S. dollar surged into positive territory for 2018 and broke past key levels against several currencies as a divergence between growth and the interest rate outlook versus other countries spurred investors to chase the currency higher. A strong dollar makes greenback-denominated oil more expensive to holders of other currencies.
"The strength of the dollar is where the pressure is coming from," said Gene McGillian, vice president at Tradition Energy.