U.N. Ambassador Susan Rice’s potential bid to become the next secretary of state appeared further in jeopardy Wednesday, with one key Republican practically warning President Obama not to send her nomination to the Senate.

“I would just ask the president to step back away from all the buzz around this, take a deep breath and decide who’s the best secretary of state for this country,” Tennessee Sen. Bob Corker said after a 90-minute meeting with Rice, who is under fire for her initial public explanation of the deadly consulate attacks in Libya.

Rice’s separate talks with Corker and Maine Sen. Susan Collins, another key Republican, marked her second day of Capitol Hill meetings in her effort to explain events surrounding the attacks Sept. 11 on the U.S. Consulate in Benghazi, Libya.

She said five days after the attacks, on several Sunday talk shows, that the strikes appeared to be “spontaneous” acts of violence that evolved from protests over an anti-Islamic film.