FILE - Secretary of State Hillary Rodham Clinton, listens to a reporter ask a question during a news conference with African Union Chairperson Nkosazana Dlamini-Zuma, not seen, after their meeting at the Department of State in Washington, in this Nov. 28, 2012 file photo. Doctors treating Secretary of State Hillary Rodham Clinton for a blood clot in her head said Monday Dec. 31, 2013 that blood thinners are being used to dissolve the clot and they are confident she will make a full recovery. (AP Photo/Manuel Balce Ceneta, File)
WASHINGTON (AP) - Hillary Rodham Clinton has formally resigned as America's 67th secretary of state, capping a four-year tenure in the office that saw her shatter previous records for countries visited.
In a letter sent to President Barack Obama on Friday shortly before she was to leave the State Department for the last time in her official capacity, Clinton thanked her former foe for the 2008 Democratic presidential nomination for the opportunity to serve in his administration. Clinton said it had been an honor to be part of his Cabinet and that she remained convinced of the "strength and staying power" of American global leadership.
Her resignation will be effective on the swearing-in of her successor, John Kerry, who will take the oath of office in a private ceremony later Friday.