Stock futures were down while oil surged after President Trump said his ceasefire with Iran was finished.
"I think it's over," Trump told reporters at a NATO summit in Turkey. "As far as I'm concerned, it's just a waste of time dealing with them."
Brent crude futures jumped more than 6% to roughly $78.50-far above their prewar levels.
Trump's comments came after the U.S. and Iran exchanged strikes and Washington reimposed sanctions on Tehran's crude sales.
"The developments have reignited concerns about energy supplies and geopolitical risk," Deutsche Bank said.
