Embattled U.N. envoy Susan Rice is dropping out of the running to be the next secretary of state after months of criticism over her Benghazi comments, she told NBC News on Thursday.

“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 Obama, saying she’s saddened by the partisan politics surrounding her prospects.

“That trade-off is simply not worth it to our country...Therefore, I respectfully request that you no longer consider my candidacy at this time,” she wrote in the letter obtained by NBC News.