WASHINGTON — Britain’s exit is expected to jolt the U.S. economy, likely rattling restive equity markets and driving up the value of the dollar. It could also weaken U.S. diplomatic leverage in Europe and upend the corporate strategies of U.S. companies based in London.

Top finance officials say the damage from the so-called Brexit alone isn’t likely to be enough to nudge the U.S. into a contraction. But as skittish investors pull out of U.K. and European markets and pour into the safety of U.S. assets, a falling pound and euro could cause the dollar to surge, further suppressing demand for American exports.