Secretary of State Hillary Rodham Clinton is "raring to go" and plans to return to work next week after medical setbacks that kept her out of public view for more than three weeks, a spokeswoman said Thursday.

Clinton's return to work will probably be brief. The White House has already picked Sen. John F. Kerry (D-Mass.) to succeed her and is expected to formally nominate Kerry within days. A Senate confirmation hearing is likely to be held within two weeks, congressional and administration officials said, although a date has not been set.

Clinton was released from a New York hospital Wednesday evening, three days after a blood clot was discovered inside her skull. Her doctors predict a full recovery from the clot and an apparently related concussion she suffered in a fall last month.

"She's sounding terrific, upbeat, raring to go," State Department spokeswoman Victoria Nuland said Thursday. Nuland said Clinton plans to be in the office next week but did not give a specific date.

Clinton's return sets in motion a quick succession of congressional appearances that had been on hold pending news of her health, with a goal of handing off to Kerry shortly before or after Inauguration Day.

Clinton plans to keep her earlier pledge to testify to House and Senate committees about the fatal attack on a diplomatic compound in Benghazi, Libya, Nuland said. No date has been set for those appearances, and they are not likely before the week of Jan. 14, two officials said.

The Libya hearings are a command performance to satisfy congressional Republicans critical of the Obama administration's handling of security in Libya before the attack and of its erroneous claim that the attack was linked to anti-U.S. protests elsewhere in the Mideast instead of to terrorists.

Clinton was too sick to present the findings of an independent inquiry into the attack during congressional hearings last month and pledged then to return in person in January.

"She is committed to testifying, and we are working with the committees on an appropriate set of dates," Nuland said.

Senate Republicans announced committee assignments Thursday that will affect the makeup of the panel Clinton would address. The administration's fiercest critic on Benghazi, Sen. John McCain (R-Ariz.), is a new member of the Foreign Relations Committee.

Sen. Lindsey O. Graham (R-S.C.), who said last week that Clinton must testify about Benghazi before the Kerry nomination moves ahead, does not sit on the panel but could hold up the Kerry nomination in the full Senate. Graham told "Fox News Sunday" that Kerry agrees that Clinton must testify.

Kerry, the current committee chair, is to be replaced by Sen. Robert Menendez (D-N.J.), who has accused the White House of being weak in the face of Iranian nuclear defiance. In 2011, he told the top State Department official managing negotiations over Iran's nuclear program that the administration was undermining its own sanctions strategy.

Kerry remains chairman for now but would step aside once his nomination becomes formal.