Who is oilman Rex Tillerson?

Donald Trump has announced that his nominee for secretary of state is Rex Tillerson, the CEO of oil company ExxonMobil.

Tillerson, who has close ties to Russia, must first be approved by the US Senate.

The BBC’s Barbara Plett Usher reports that in picking Mr Tillerson, a Texas oilman with no government experience, Mr Trump is sending his clearest sign yet that he intends to run the government like a business.