Maduro has such a close relationship with Chavez that he often seems to know how the president comes down on just about any issue, and he often is picked to speak on the president's behalf.
Chavez's next six-year term begins in January. He's expected to start making other changes in Cabinet posts while naming allies to run for gubernatorial posts in state elections on Dec. 16.
Jaua is running to be governor in Miranda state, which includes part of Caracas and is currently controlled by opposition leader Henrique Capriles, who was defeated by Chavez in Sunday's presidential election.
Chavez won 55 percent of the vote, beating Capriles by 11 percentage points, which was the president's smallest re-election margin to date.
Chavez said his next term would bring more progress in moving toward a socialist system. He said it's time for a "renewal in the socialist project" and called for his government to become more efficient in solving problems.
"Many things must be corrected," Chavez said.