Susan Rice, the U.S. ambassador for the U.N., withdrew her name Thursday from consideration to be secretary of state in the face of implacable opposition from Senate Republicans.

"If nominated, I am now convinced that the confirmation process would be lengthy, disruptive and costly—to you and to our most pressing national and international priorities," Rice wrote in a letter to President Barack Obama, NBC News first reported.

Obama soon confirmed her withdrawal in a statement, saying, "While I deeply regret the unfair and misleading attacks on Susan Rice in recent weeks, her decision demonstrates the strength of her character, and an admirable commitment to rise above the politics of the moment to put our national interests first."