By Susan Heavey and Doina Chiacu WASHINGTON (Reuters) -The United States is open to imposing sanctions on Russia’s oil and gas industry but going after its exports now could help Moscow, the White House said on Wednesday as oil prices touched eight-year highs and supply disruptions mounted. The White House is considering hitting Moscow’s vast energy sector over Russia’s invasion of neighboring Ukraine, but the impacts on global oil markets and U.S. energy prices are also key factors. “We don’t have a strategic interest in reducing global supply of energy … that would raise prices at the gas …