Donald Trump is expected to nominate ExxonMobil CEO Rex Tillerson as his secretary of state, two sources close to the transition process told NBC News on Saturday. The 64-year-old veteran oil executive has no government or diplomatic experience. The pick would put to rest weeks-long speculation of who would earn the post as the U.S.'s top diplomat. Tillerson would be fourth in line to the presidency. Tillerson will be paired with former U.N. Ambassador John Bolton as his deputy secretary of state, one of the sources added, with Bolton handling day-to-day management of the department.