Hugo Chavez 'battling for his life'
"Our commander is sick because he gave his life for those who don't have anything," he said on Venezuelan TV.
Mr Chavez has not been seen in public since he had further cancer surgery in Cuba in December and is reported to have a severe a respiratory infection.
The government has previously said Mr Chavez, now back in Venezuela, is running the country from the hospital.
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, according to BBC.
He was re-elected for another six-year term in October 2012, but the Supreme Court ruled that his swearing-in could be delayed because of his illness.
Speaking on Thursday, Mr Maduro said the president "didn't take care of his health because he gave his body and soul" to the people.
"He's battling for his life, for his health, and we are there with him," he said.
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