WASHINGTON, Dec 12 (Reuters) - Contenders for President-elect Donald Trump's two top diplomatic roles, Rex Tillerson and John Bolton, will face a tough review in confirmation hearings in a U.S. Senate led by Trump's fellow Republicans.
Lawmakers from both major political parties have raised concerns about Tillerson, president and chief executive of Exxon Mobil Corp who has close ties with Russia and has met Russian President Vladimir Putin several times, and about Bolton, a former U.S. ambassador to the United Nations who has voiced hawkish views on Iraq and Iran.
Tillerson emerged over the weekend as Trump's expected pick for secretary of state. Bolton has been mentioned as a possible No. 2 State Department official. Trump is due to succeed President Barack Obama on Jan. 20.
Washington and Moscow are at odds over a range of issues that include Syria, Ukraine and NATO's presence in eastern Europe.
In television interviews on Monday, Trump's senior adviser Kellyanne Conway said Tillerson is a "leading candidate" for the top diplomat job and a decision may come this week.
During a Monday news conference, Senate Majority Leader Mitch McConnell, a Republican, 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 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."
"He'll be questioned thoroughly, should he be the nominee, and all of these allegations and talks about his closeness with Putin will come forward," Schumer said.
During Trump's campaign for the Nov. 8 election, Democrats and longtime government officials voiced alarm when Trump repeatedly praised Putin, suggesting they would "get along very well."
On Sunday, Senator John McCain, a Republican who lost the 2008 presidential race to Obama, said of Tillerson: "It's a matter of concern to me that he has such a close personal relationship with Vladimir Putin and obviously they've done enormous deals together. That would color his approach to Vladimir Putin and the Russian threat."
McCain, now chairman of the Senate Armed Services Committee, added that Tillerson would get a fair confirmation hearing.
Bolton also has raised bipartisan concern. On Sunday, Republican Senator Rand Paul said he would work to stop Bolton from being confirmed to any Trump administration post.
"His world view 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; Writing by Richard Cowan; Editing by Howard Goller