Susan Rice, the US ambassador to the UN, has withdrawn her name for consideration for the position of US secretary of state.

Rice was in the running to replace current Hillary Clinton who will step down from her post in January.

The envoy, who is close to US President Barack Obama, had been the target of Republican attacks on the administration's handling of the raid on the US consulate in Benghazi, Libya on September 11 this year.

"Those of you who know me know that I'm a fighter, but not at the cost of what's right for our country," Rice wrote on Twitter on Thursday.

'Passionate public servant'

In a letter to Obama on Thursday, Rice said: "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".

Al Jazeera's Rosiland Jordan says Rice has become "a huge political liability for the Obama administration"

Rice said she was saddened by the partisan politics surrounding her prospects.

Obama said in a statement: "Today, I spoke to Ambassador Susan Rice, and accepted her decision to remove her name from consideration for Secretary of State.

"For two decades, Susan has proven to be an extraordinarily capable, patriotic, and passionate public servant."

He added that Rice's decision to withdraw her name had reflected her strength of character and an ability to rise above politics.

Al Jazeera's Alan Fisher, reporting from Washington said Obama has a series of appointments and also negotiations over the looming fiscal cliff which all have to be agreed with the Republicans.

"Obama, by accepting the withdrawal of Rice, shows the President is choosing his battles carefully with the Republicans," said our correspondent.

Rice, 48, has been the US Permanent Representative to the UN since 2009, her withdrawal leaves Senator John Kerry as a possible candidate for the job.

Source: Al Jazeera and agencies