President Donald Trump signed a directive that aims to ramp up economic pressure on Iran, following through on pledges to reverse what he has cast as a lax sanctions enforcement regime under his White House predecessor.

U.S. President Donald Trump on Tuesday restored his "maximum pressure" campaign on Iran that includes efforts to drive its oil exports down to zero in order to stop Tehran from obtaining a nuclear weapon.

U.S. oil prices slipped on Tuesday on tariff drama between Washington and Beijing, then pared losses after an official said President Donald Trump plans to restore his "maximum pressure" campaign on Iran in a bid to drive down Iranian oil exports to zero.