CARACAS, Venezuela—Hugo Chavez has delegated some administrative responsibilities to Venezuela's vice president, allowing his close confidant to make decisions related to the budget, expropriations and government debt.

Chavez passed on the duties to Vice President Nicolas Maduro on Dec. 8, three days before the socialist leader underwent cancer-related surgery in Cuba. The measure took effect Wednesday upon its publication in the Official Gazette.

Chavez traveled to Cuba after tests had found a return of malignant cells in the same area where tumors were removed. Since his Dec. 11 surgery, he has remained in Cuba.

The president has been silent since the operation, raising doubts among Venezuelans regarding his health.

Maduro announced on Christmas Eve that Chavez was walking and talking, but the news did not ease uncertainty surrounding his condition.