Story highlights John Bolton is encountering headwinds from fellow Republicans

Members of the foreign policy establishment have proposed alternative candidates for the job

Washington (CNN) Donald Trump's transition team has expanded its search for the second-in command at the State Department, several sources familiar with the deliberation told CNN, as one of the leading candidates is facing resistance.

The sources say the transition appears to be struggling with who they want for the deputy secretary of state post, just as they did for the top job before Trump tapped retiring ExxonMobile CEO Rex Tillerson.

Former Secretary of State Condoleezza Rice, former National Security Advisor Steve Hadley and Bob Gates, former secretary of defense, all of whom know Tillerson, recommended him for the post after Vice-President elect Mike Pence asked their advice about possible candidates.

It is not clear if any appointment would come before Tillerson is confirmed.

John Bolton, a leading candidate to be Tillerson's second-in-command at the State Department, is encountering headwinds from fellow Republicans, including from Trump's choice to lead the agency. The brusque and opinionated Bolton is as loved in some quarters for his uncompromising conservatism as he is loathed in others -- particularly among foreign service diplomats in the State Department -- for his views and style.

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