WASHINGTON - The US State Department said on Thursday that Secretary of State Hillary Clinton is aiming to return to her office as early as next week following treatment for blood clot in her head.

"She's resting at home. Some of the senior staff who spoke to her about half an hour ago say that she's sounding terrific, upbeat, raring to go," department spokeswoman Victoria Nuland said at a regular news briefing.

"She's looking forward to getting back to the office. She is very much planning to do so next week," she added.

And Clinton "is committed to testifying" in Congress over the deadly attack on the US consulate in Benghazi, Libya, an appearance she had set for December 20 but canceled later due to her illness, Nuland said.

Clinton, 65, was discharged from a New York hospital Wednesday evening following days of treatment of a blood clot in a vein in her head, which was discovered after she sustained a concussion two weeks ago when she fainted and hit her head.

As the State Department put it, the top American envoy fainted as a result of dehydration caused by a stomach virus developed during her European tour last month.

Since taking office in January 2009, Clinton has visited 112 countries with a total mileage of over 950,000 miles, making her one of the most-traveled secretaries of state in American history.

She has stated her intention to step down at the start of President Barack Obama's second term in January, and the president has nominated Senator John Kerry to succeed her.