The Venezuelan government has announced that President Hugo Chavez is in a fragile state of health with increased breathing problems.
Information Minister Ernesto Villegas said on Monday that Mr Chavez, 58, is suffering from a new, severe respiratory infection following cancer surgery.
He returned to Venezuela in February after being treated for cancer in Cuba on 11 December last year, but has not appeared in public since.
Many Venezuelans have been demanding full details about his health, the BBC reports.
Mr Villegas read the latest brief update on national television, saying Mr Chavez was being treated at a military hospital in Caracas and that his breathing problems have worsened.
Mr Chavez, who has been in office for 14 years, is believed to have cancer in his pelvic area, but his exact illness has never been disclosed, the BBC reports.
In June 2011, he announced that he had cancer and has undergone four operations since then, as well as chemotherapy and radiation therapy.
The president was re-elected for another six-year term in October 2012, but the Supreme Court ruled that his swearing-in on 10 January could be delayed due to his illness.