Updated 3:53 PM ET
CARACAS, Venezuela - President Hugo Chavez said Tuesday that doctors in Cuba have found a new lesion in the same place where he had cancer surgery last year, and he will require surgery.
"It is a small lesion of about 2 centimeters (less than 1 inch) in diameter, very clearly visible," Chavez told state television.
The announcement throws new uncertainty over the country's politics because the socialist leader is seeking re-election this year, hoping to extend his more than 13 years in power.
He did not say when he would undergo the surgery, other than "in the coming days."
Chavez, 57, said the new surgery should be less complicated than what he underwent in Cuba in June, when doctors removed cancerous tumor from his pelvic region. From July to September, he received four rounds of chemotherapy, both in Cuba and in Venezuela, and he has since said that tests show he is cancer-free.
On Tuesday,he denied rumors the cancer had spread aggresively.
"I completely deny what's going around that I have metastasis in the liver or I don't know where, that the cancer has spread all over my body and that I'm already dying."
He has never specified the cancer's exact nature or location.
Speaking from his home state of Barinas, Chavez said he decided to speak publicly "because there are so many rumors, including rumors (the cancer) has been spreading."
He had been out of public sight since Friday, and unconfirmed reports that he spent the weekend in Cuba prompted a denial Monday from Communications Minister Andres Izarra.
"Regarding the rumors, dirty war from the gutter," Izarra tweeted.
In recent weeks, Chavez has recovered the hair that he shaved while undergoing chemotherapy and he has appeared vigorous, returning to his full schedule of activities, including marathon television appearances.
He has assured Venezuelans that he is in fine shape to gain what would be his third re-election in Oct. 7 elections against opposition candidate Henrique Capriles.
"I am in good physical shape to confront this new battle," Chavez said, adding that he would provide Venezuelans with more details after meeting with his Cabinet on Wednesday.
He did not mention the extent to which the surgery and recuperation from it might affect his campaigning.