US equity indexes traded lower around midday Wednesday as crude oil futures and government bond yields rose amid concern that Iran's blockade will be extended to force Tehran into a peace deal.

The Dow Jones Industrial Average fell 0.7% to 48,789.2, with the S&P 500 down 0.2% to 7,122.9. The Nasdaq Composite was 0.2% lower at 24,620.7.

President Donald Trump has instructed aides to prepare for an extended blockade of Iran, US officials told The Wall Street Journal. In recent meetings, including a Monday discussion in the Situation Room, Trump opted to continue squeezing Iran's economy and oil exports by preventing shipping to and from its ports, the WSJ said.

Trump assessed with his aides that the other options open to him -- resume bombing or walk away from the conflict -- carried more risk than maintaining the country's blockade, the officials told the WSJ.

"Iran can't get their act together. They don't know how to sign a nonnuclear deal. They better get smart soon!" Trump said in a Truth Social post Wednesday.

Meanwhile, West Texas Intermediate crude oil futures jumped 4.9% to $104.86, and Brent crude futures surged 5% to $116.85 amid concern that Trump's policy will prolong disruption in the Strait of Hormuz, the chokepoint for 20% of global crude oil flows.