By Nandita Bose, Matt Spetalnick and Alexandra Alper WASHINGTON (Reuters) – The United States targeted Russian banks and elites with a new round of sanctions on Wednesday, including banning Americans from investing in Russia, in response to what President Joe Biden condemned as Russian “atrocities” in Ukraine. The new sanctions hit Russia’s Sberbank, which holds one-third of Russia’s total banking assets, and Alfabank, the country’s fourth largest financial institution, U.S. officials said. But energy transactions were exempted from the latest measures, they said. The United States is also san…