Russian President Vladimir Putin and U.S. President Donald Trump are likely to discuss the sanctions that Washington imposed on Russia over the conflict in Ukraine when the two leaders speak by telephone on Saturday, a senior White House aide said. Trump has said in the past that, as part of a rapprochement he is seeking with Russia, he is prepared to review sanctions that his predecessor, Barack Obama, imposed on Russia over its 2014 annexation of Ukraine’s Crimea Peninsula.