File photo of Barack Obama
The US Senate Foreign Relations Committee on Tuesday confirmed Roberta Jacobson's nomination as ambassador to Mexico, months after President Barack Obama tapped her for the post.
Her nomination, which the committee approved by a vote of 12 to 7, must now be confirmed by the full Senate where she faces Republican opposition.
As assistant secretary of state for Western Hemisphere Affairs, Jacobson played a central role in the diplomatic reconciliation between the United States and Cuba.
Senator Ben Cardin, the top Democrat on the panel, said she was "uniquely qualified" to be ambassador to Mexico, the United States' third largest trading partner and second biggest energy supplier.
But critics of the rapprochement with Cuba opposed the nomination.
"We need an ambassador in Mexico City that has the trust of Congress for this important post," said Senator Marco Rubio, who is running for president.
"I do not believe that Ms Jacobson is that person and will oppose her confirmation."
New Jersey Senator Robert Menendez, another critic of the Cuba policy, was the sole Democrat to vote against her.
"I cannot support her nomination," Menendez said.
"I found her not to be the advocate she promised to be for the region and against authoritarianism."
Jacobson served as director of the State Department's Office of Mexican Affairs Department from 2003 to 2007, then as deputy assistant secretary of state for Canada, Mexico and the North American Free Trade Agreement.
From 2010-2011, she was principal deputy assistant secretary of state for Hemispheric Affairs.
Obama nominated her to be his ambassador to Mexico in June but the Senate had held up the critical appointment.
"We've waited long enough," said Senator Jeff Flake, a Republican from the border state of Arizona.