Crude oil prices surged higher on Monday amid rising speculation about the impact of Ukraine's offensive around Kharkiv on supply of Russian oil.
Uncertainty about revival of the Iranian nuclear deal also raised concerns over Iranian crude coming into the world oil market.
Traders also reacted to the data from the U.S. Department of Energy that showed U.S. emergency oil stocks fell 8.4 million barrels to 434.1 million barrels in the week ended Sept. 9, its lowest since October 1984.
A weak dollar contributed as well to the jump in oil prices. The dollar index dropped to amid expectations the data on U.S. inflation, due on Tuesday, will show
West Texas Intermediate Crude oil futures for October ended higher by $0.99 or about 1.1% at $87.78 a barrel.
Brent crude futures were up $1.12 or 1.21% at $93.96 a barrel a little while ago.
European diplomats are reportedly expressing "serious doubt" that Tehran is genuinely seeking a revival of the 2015 nuclear deal.