Cristina Kirchner, Argentina's president, has been recovering in a private hospital in the capital Buenos Aires after successful surgery to remove a blood clot on her brain, officials have said.
A government spokesman said on Tuesday that the surgery was successful and a report described her as recovering "favourably" in an intensive care unit of the hospital.
"It went very well. The president is in good spirits and is already in her room," said undersecretary for public communication Alfredo Scoccimarro.
Kirchner, 60, was diagnosed over the weekend with a "chronic subdural hematoma" resulting from a blow to the head sustained in a fall in mid-August.
The surgery involved drilling small holes through the skull to remove old blood and recovery can take three months or more.
Lucia Newman, Al Jazeera's correspondent in Buenos Aires, said that the president will be in the hospital's intensive care unit for 48 hours, and will take several weeks to recover from the operation.
"It is unclear how long she will be away from office," she added.
Buenos Aires Governor Daniel Scioli, who has announced his bid to succeed Kirchner in 2015, was among many Argentine politicians wishing her a rapid recovery.
"If God desires it, she's going to be back with us very soon, fully functioning."
Supporters of the president gathered outside the hospital where they left flowers and "Get well" messages around a flag-draped photograph of Kirchner and her late husband Nestor, who preceded her as president.
"Strength, Cristina," "The country and the youth are with you," and "You are irreplaceable," read placards.
Kirchner has had several bouts of low blood pressure since coming to office in 2007, and underwent surgery last year to remove her thyroid glands after being misdiagnosed as having cancer.
The fact that the president is out of commission and is unable to campaign does not bode well for the ruling party
The current medical setback comes at a sensitive political moment, with Argentines going to the polls on October 27 to cast ballot in legislative elections that will set the political direction for the country halfway through Kirchner's second and last term.
At stake are half the seats in the Lower House of Congress and a third of the Senate. Kirchner's Peronist party currently controls both Houses, but showed signs of weakness in primaries earlier this year.
Al Jazeera's Lucia Newman said that "the fact that the president is out of commission and is unable to campaign does not bode well for the ruling party".
Vice President Amado Boudou, a former economy minister from 2009 to 2011, has assumed leadership of the government in Kirchner's absence, although without a formal transfer of presidential powers.
A full medical leave would require Congressional approval.