Supreme Court Justice Elena Kagan will swear in John Kerry as secretary of state on Friday afternoon, state department spokeswoman Victoria Nuland said Wednesday.
"He knew her well from the Clinton White House and from Massachusetts," Nuland said.
Kerry said in his resignation letter he will step down from the Senate at 4 p.m. Friday, which is also Secretary of State Hillary Clinton's last day in her post. He was confirmed by the Senate on Tuesday.
When Kerry introduced Kagan to the Senate Judiciary Committee for her 2010 confirmation hearings, he noted he worked closely with her on a tobacco bill when she was a counsel and adviser to then-President Bill Clinton.
"Elena became the administration's point person," he said. "When we started out, no one gave us hope of getting close to passage. But Elena camped out in the vice president's office off the Senate floor, shuttling back and forth to the White House. She worked night and day, working every angle, thinking through every approach."
He described her attitude on the bill as "classic Elena -- she saw a path forward when most folks saw nothing but deadlock."
Kerry was born in Colorado and Kagan in New York, but both attended law school in Massachusetts - he, Boston College Law School, and she, Harvard University. Kagan would later teach at Harvard law, then serve as the school's first female dean until her appointment by President Barack Obama in 2009 as solicitor general.
He has lived in the Bay State since the 1970s and was first elected by Massachusetts voters to the U.S. Senate in 1984.
At her confirmation hearings, he told senators, "I'm glad that in these next days you'll get the chance to know Elena as so many of us have in Massachusetts."
Kerry's office said Tuesday he would deliver a farewell address in the Senate on Wednesday afternoon.