U.S. hits oil giant Rosneft, other firms with toughest Russia sanctions

U.S. President Barack Obama pauses while he delivers remarks about Ukraine while in the press briefing room at the White House in Washington, July 16, 2014. REUTERS/Larry Downing

WASHINGTON (Reuters) - President Barack Obama imposed the biggest package of U.S. economic sanctions yet on Russia on Wednesday, hitting Russia's largest oil producer Rosneft and other energy, financial and defense firms, with what he called significant but targeted penalties.

Obama's latest round of sanctions came after close consultations with European leaders, who announced a less-ambitious package. The ultimate impact of the U.S. sanctions likely depends on whether the European Union follows suit.