The message delivered Thursday night was blunt: The United States recognized Venezuela’s opposition presidential candidate as the winner in Sunday’s election and dismissed a declaration by election officials that the country’s autocrat, President Nicolás Maduro, had won.

The government has not produced any data supporting his claim of victory, the Biden administration said, while his rival, Edmundo González, had tallies from a majority of voting machines that his team said show he had won by an “insurmountable margin.” The New York Times has not verified those tallies.

The U.S. declaration ratcheted up the international condemnation of a vote riddled with irregularities and was an attempt to warn Mr. Maduro that the world would not accept a farce. Even some of Mr. Maduro’s fellow leftist leaders in Latin America have expressed grave doubts about his claim of victory.

But will it matter?

There is widespread skepticism that foreign pressure will affect Mr. Maduro’s grip on power, at least in the short term.

Already, protests in support of Mr. González have sputtered out, as security forces and pro-government gangs have responded with force. At least 17 people have died, including one soldier. About 750 people have been arrested in the demonstrations, according to the country’s attorney general.