Fears have been raised over the political future of the 58-year-old president who has already had three cancer operations in Cuba since the middle of last year.
News of more surgery will likely raise new doubts about his political future and the fate of his self-styled "revolution" in the OPEC nation.
In his comments on Saturday, Chavez sat alongside members of his Cabinet, including Vice President Nicolas Maduro and Congress head Diosdado Cabello, two close and powerful allies who might look to replace him if Chavez were to leave office.
More top news
Searches are continuing for victims, with around 600 people still missing and 3,000 left homeless after the disaster.
The man who drove the van that ploughed into pedestrians killing 13 people was unharmed and is still on the run, police believe.
Donald Trump has said American culture is being "ripped apart" by efforts to remove Confederate memorials from parts of the country.