WASHINGTON - John Kerry has been sworn in as America's secretary of state, replacing Hillary Rodham Clinton.
The former Massachusetts senator and 2004 presidential candidate was sworn in Friday by Supreme Court Justice Elena Kagan. He is the 68th secretary of state.
Clinton's resignation became effective at 4 p.m. EST, when Kerry was sworn in. She departs after a four-year tenure that saw her shatter records for the number of countries visited.
In a letter sent to President Barack Obama shortly before she left the State Department for the last time in her official capacity, Clinton thanked her former opponent 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.
"I am more convinced than ever in the strength and staying power of America's global leadership and our capacity to be a force for good in the world," she said in the letter.