WASHINGTON — President-elect Donald Trump moved closer to nominating Exxon Mobil CEO Rex Tillerson as his secretary of state Saturday, meeting privately with the business leader for the second time in a week. Trump’s transition team cautioned that no announcement was expected over the weekend. Trump has privately signaled that he plans to tap Tillerson for the powerful Cabinet post, but had not formally offered him the job as of Saturday afternoon, according to people who have spoken with Trump and his transition team.