El Informe reported Maduro said he had traveled to Havana to meet with Hugo's family and medical team.
El Universal reported the vice president said Chavez "is undergoing major complementary therapies, extremely complex and hard."
The 58-year-old Chavez underwent his latest cancer surgery Dec. 11 and has not returned from Cuba since, missing his scheduled inauguration to a new term in office last month.
Maduro said he and other Cabinet members continue to shuttle between Caracas and Havana to confer with Chavez on government matters.
Senate Democrats to pull all-nighter on climate change
Jessica Simpson shares three-way kiss with friends in photo