President Hugo Chavez, who has not been seen publicly in a month since undergoing a complex cancer surgery in Cuba, will not be back in Venezuela on Thursday to be sworn in for a fourth term, his government announced Tuesday.

Vice President Nicolas Maduro said in a letter read on national television that Chavez would extend his “post-surgery recovery process beyond Jan. 10 of this year,” the date on which the constitution says the president should be inaugurated before the country’s legislature.

“Because of this he will not be able to appear on that date before the National Assembly,” said the letter, which was read before lawmakers by the president of the assembly, Diosdado Cabello. The letter went on to say that the circumstances of Chavez’s absence trigger application of a constitutional article permitting him to take the oath at a later, undetermined date.