(FILES) This file photo taken on June 2, 2015 shows Exxon Mobil Chairman and CEO Rex Tillerson addressing the World Gas Conference in Paris. President-elect Donald Trump on Tuesday tapped ExxonMobil chief Rex Tillerson, an oilman with deep ties to Russia, as his secretary of state. Tillerson's nomination comes just days after a secret CIA report accused Russia of interfering with the US election in favor of Trump, in a development which could complicate his confirmation. / AFP PHOTO / ERIC PIERMONT