WASHINGTON (CNN) -- ExxonMobil Chairman and CEO Rex Tillerson is the leading candidate for Secretary of State in a Donald Trump administration, multiple sources familiar with the transition process tell CNN on Saturday.
The final announcement is expected to be made in the middle of next week, according to a source close to the campaign. A source also said Mitt Romney is still in the running, at the urging of Reince Priebus, who will be Trump's chief of staff.
Trump's spokesman Jason Miller tweeted Saturday that there would be "no announcements on Secretary of State until next week at the earliest."
Tillerson, who met with Trump in New York Saturday, is considered one of the faces of Big Oil globally.
He was originally considered a long shot to be America's top diplomat, but Trump is reportedly intrigued by the oil man's view of the world.
As head of the world's most valuable oil company, Tillerson could be a controversial pick due to concerns about climate change and his ties to Russian President Vladimir Putin.
Sen. John McCain told CNN on Saturday that he had concerns about Tillerson's relationship to Russia and wants to hear his answers to such during his would-be hearing before making up his mind.
"What about all the other things -- right now, the targeting of hospitals by Russian aircraft with precision weapons in Syria, in Aleppo?" the Arizona Republican asked ahead of the Army-Navy football game. "Those are the kind of questions that we need to ask about the relationship with Vladimir Putin."
In 2011, Exxon signed a deal with Russian oil giant Rosneft to provide access to lucrative oil resources in the Arctic.
Rosneft's largest shareholder is the Russian government. Putin attended the Exxon signing ceremony and later awarded Tillerson the country's Order of Friendship.
Other contenders for the secretary of state position include former CIA Director David Petraeus; Senate Foreign Relations Committee Chairman Bob Corker; and former UN Ambassador John Bolton.