CARACAS, Venezuela — Fresh off his re-election in what critics called a rigged vote, President Nicolás Maduro of Venezuela on Tuesday ordered the top American diplomat and his deputy expelled, describing them as conspirators against his government.

In a televised address, Mr. Maduro gave the diplomats, Todd D. Robinson, who is the United States Embassy’s chargé d’affaires, and Mr. Robinson’s No. 2, Brian Naranjo, 48 hours to leave, declaring them both persona non grata.

“This is in protest, in defense of Venezuelan dignity! Enough with the conspiracies,” Mr. Maduro said at an event where officials certified his re-election to a term ending in 2025.

The State Department said in a statement, “We reject completely the false allegations made by Maduro against Chargé Robinson and Deputy Chief of Mission Naranjo.”