A key US Senate committee has narrowly approved Rex Tillerson as secretary of state after leading Republican Senator Marco Rubio dropped his opposition.
Mr Rubio sparred with Mr Tillerson, the former head of Exxon Mobil, during confirmation hearings, accusing him of being soft on Russia.
A full vote will now be held in the Senate, where Republicans dominate.
Mr Tillerson, a 64-year-old Texan oilman, knew Russian President Vladimir Putin as a businessman.
But he has since criticised Russia for its annexation of Crimea.
He was chosen by Donald Trump, who was sworn in as America’s 45th president on Friday.
In its vote, the Senate Foreign Relations Committee split along party lines, with all 11 Republicans voting in favour and all 10 Democrats against.
Mr Rubio said earlier that although he had doubts over the choice, he believed a new president was entitled to deference in assembling his cabinet.
“Despite my reservations, I will support Mr Tillerson’s nomination in committee and in the full Senate,” said Mr Rubio.
He had challenged Mr Tillerson over his refusal to call President Putin a “war criminal” and his failure to condemn strongly enough human rights violations in Saudi Arabia and the Philippines.
Mr Rubio was among the candidates who fought Mr Trump in the battle for the Republican presidential ticket.
Senator Ben Cardin, the committee’s top Democrat, said earlier that he would not vote for Mr Tillerson, also over his position on Russia, as well as other issues.
He also suggested that Mr Tillerson’s “business orientation” could “compromise his ability as secretary of state to forcefully promote the values and ideals that have defined” America.
While critics raise concern about his ability to trade in his corporate interest for a national one, some supporters suggest the former CEO’s background as a global dealmaker may bring fresh perspective to the nation’s top diplomatic post.
