Washington - Secretary of State Hillary Rodham Clinton was hospitalized in New York on Sunday after doctors monitoring her recovery from a concussion discovered a blood clot, according to a statement from her office.

The statement said that "in the course of a follow-up exam, Secretary Clinton's doctors discovered a blood clot had formed, stemming from the concussion she sustained several weeks ago. She is being treated with anti-coagulants and is at New York-Presbyterian hospital so that they can monitor the medication over the next 48 hours.

"Her doctors will continue to assess her condition, including other issues associated with her concussion. They will determine if any further action is required."

Clinton aide Philippe Reines, who issued the statement, declined to provide further details.

Reines said on Thursday that Clinton's recuperation was continuing and that she was expected to resume her office schedule this week.

The State Department first disclosed Clinton's concussion on Dec. 15, saying that she had fallen at her home. The department said that the fall resulted from dehydration caused by a stomach virus. Aides and doctors said that Clinton's concussion was diagnosed on Dec. 13 and that she has not been seen in public since.

Clinton canceled an overseas trip and scheduled testimony before Congress about the Sept. 11 attack on a U.S. diplomatic compound in Benghazi, Libya. She also did not appear at the White House on Dec. 21, when President Barack Obama introduced Sen. John Kerry, D-Mass., as his nominee to succeed Clinton, 65.

Republicans have said they are likely to hold up Kerry's nomination hearing until Clinton testifies about the Benghazi attack, but the impact of this new disclosure was unclear.

Clinton said last summer that she would not serve a second term if Obama was re-elected.