Oil prices rose on Wednesday, with international benchmark Brent crude futures briefly crossing the $100 threshold, as escalating tensions between the U.S. and Iran fueled concerns over further disruptions to Middle East energy supplies.

Futures for Brent crude were last seen trading at around $99.93 a barrel, after rising to $100.01 a barrel at around 3:20 a.m. ET. The contracts last rose above $100 in July.