President-elect Donald Trump is tapping ExxonMobil chief executive Rex Tillerson to be the nation’s next secretary of state — an appointment that could prompt a big confirmation fight.

The multinational oil company Tillerson leads has very large prospects in Russia, which right now are by official U.S. foreign policy — sanctions against Russia. Critics say that creates too many conflicts of interest for Tillerson.

Correction (Dec. 14, 2016): A previous headline misspelled ExxonMobil.