Venezuela’s highest court ruled on Thursday that the country’s authoritarian leader, Nicolás Maduro, won the July 28 presidential election, despite overwhelming evidence that Mr. Maduro’s opponent garnered the most votes.

The decision by the Supreme Tribunal of Justice asserted that Mr. Maduro’s claim to victory was based on a report from a group of “national and international experts” and was “supported by the tally reports issued by each of the vote machines.”

But the court — stacked with Maduro allies — did not share any tallies to back up this claim, despite demands from thousands of Venezuelans who have protested in the streets, as well as many in the international community, that his government produce evidence of his victory.

The decision surprised few Venezuelans, as the court has long been used to rubber-stamp the policies of Mr. Maduro, who is likely to use this ruling to strengthen his claim to the presidency. His new term is scheduled to begin in January and run through 2031.

Mr. Maduro is also likely to use the decision to argue that he should not engage in negotiations with the United States, Colombia and Brazil, which have all sought to convince his government to publish evidence of his claim to victory, recognize the actual result of the vote and agree to a power transition if the tally shows a loss.

On election night last month, the country’s Maduro-friendly election council said that Mr. Maduro had won more than 50 percent of the vote, but did not provide any evidence to back this up.