By Doina Chiacu and Gina Cherelus
WASHINGTON/NEW YORK (Reuters) - Exxon Mobil Chief Executive Rex Tillerson, the front-runner to be named secretary of state in President-elect Donald Trump's administration, faces a struggle getting confirmed by U.S. senators concerned about his close ties to Russia.
Lawmakers from both major parties also raised questions on Monday about former United Nations Ambassador John Bolton, who has been mentioned as a possible No. 2 State Department official and has voiced hawkish views on Iraq and Iran.
Republicans and Democrats said Tillerson, who is also president of Exxon Mobil Corp, would be asked about his ties to Russia, having met President Vladimir Putin several times. He won fresh praise from Moscow on Monday.
In 2013, Putin bestowed a Russian state honor, the Order of Friendship, on Tillerson, citing his work "strengthening cooperation in the energy sector."
Fox News, citing unnamed sources, reported on Monday that Tillerson will be nominated as secretary of state. Trump said on Twitter he would name his pick on Tuesday morning, but offered no further information.
In television interviews, senior adviser Kellyanne Conway said Tillerson was a "leading candidate" for the top diplomat job.
Senator John McCain, a leading foreign policy voice and 2008 Republican candidate for president, told Reuters in an interview: “I have concerns. It’s very well known that he has a very close relationship with Vladimir Putin.”
Calling Putin "a KGB agent who is bent on restoring the Russian Empire,” McCain said he would await confirmation hearings if Tillerson is nominated before making a judgment on the nomination.
Another Republican, Senator Marco Rubio, who serves on the Senate Foreign Relations Committee that would review a Tillerson nomination, has voiced similar worries.
Renewed allegations of Russian hackers meddling in the Nov. 8 election, coupled with Trump's stated admiration of Putin, have stoked concern. Washington is at odds with Moscow over a range of issues that include Syria, Ukraine and NATO's presence in eastern Europe.
Trump is due to succeed Democratic President Barack Obama on Jan. 20. During Trump's presidential campaign, Democrats and longtime government officials voiced alarm when Trump repeatedly praised Putin.
BOLTON ALSO A CONCERN
Republican Senate Majority Leader Mitch McConnell said he was optimistic Trump's nominees would be confirmed by the Senate, but he declined to comment on any future nominees such as Tillerson.
McConnell called all of Trump's choices so far "pretty impressive."
Senator Charles Schumer, the incoming Senate Democratic leader, told CBS "This Morning" that "The bottom line is, every one of these nominees, particularly a guy like Tillerson, needs a thorough, thorough hearing."
"Talks about his closeness with Putin will come forward," Schumer said.
Bolton also has generated bipartisan concern. On Sunday, Republican Senator Rand Paul said he would work to stop Bolton from being confirmed to any Trump administration post.
"His worldview is naive," Paul said on ABC’s “This Week.” "He still believes in regime change. He's still a big cheerleader for the Iraq war. He's promoted a nuclear attack by Israel on Iran. He wants to do regime change in Iran."
In 2005, then-President George W. Bush installed Bolton as U.S. ambassador to the United Nations in a temporary "recess appointment" that sidestepped U.S. Senate confirmation. He took that step after Democrats used procedural rules in place at the time to block the nomination.
Bolton left the job at the end of 2006 when the temporary appointment was ending.
Since then, Senate rules have changed, making it harder for a minority of senators to stop judicial and executive branch nominations. Republicans will hold a 52-48 majority in the Senate session that begins on Jan. 3.
(Reporting by Doina Chiacu, Matt Spetalnick and Jonathan Landay in Washington and Gina Cherelus in New York; Writing by Richard Cowan; Editing by Howard Goller and Jonathan Oatis)