An official Venezuela presidential account provided details on Chavez's death and later tweets a link to the video of the television announcement.
In Chavez's final tweet on Feb. 18, he said he had faith in Christ and confidence in his doctors and nurses.
Most U.S. lawmakers were critical of Chavez, and see his death as an opportunity for change in Venezuela. Some also tweeted in Spanish.
Rep. Jose Serrano, a Democrat representing the South Bronx, praised Chavez. Serrano and Chavez worked together on using Venezuelan heating oil to heat poor households.
Other heads of state issued statements.
The president of Colombia said he was profoundly saddened by the death of Chavez
The president of El Salvador also expressed regrets, as did the president of the Dominican Republic.
France's President Hollande expressed his condolences to the people of Venezuela.
U.K.'s foreign secretary issued a statement.
Canada's prime minister tweeted a statement offering "condolences to the people of Venezuela on the passing of President Chávez."