The United States has said "it is clear" that President Nicolas Maduro lost the popular vote in Venezuela's election last week, as a key opposition leader said she is in hiding in fear for her life. "Given the overwhelming evidence, it is clear to the United States and, most importantly, to the Venezuelan people that Edmundo González Urrutia won the most votes in Venezuela's July 28 presidential election," Secretary of State Antony Blinken said in a statement. "In addition, the United States rejects Maduro's unsubstantiated allegations against opposition leaders. Maduro and his representatives' threats to arrest opposition leaders, including Edmundo González and María Corina Machado, are an undemocratic attempt to repress political participation and retain power," Blinken added. Protests broke out across Venezuela after the country's electoral body, which is stacked with regime allies, announced Maduro as the winner with 51% of the votes. The election was seen as the most consequential in years, with Venezuela's stalling democracy and hopes of recovering its shattered economy on the line. Many young opposition supporters said they would leave the country if Maduro was re-elected, pointing to the devastating collapse of Venezuela's economy and violent repression under his rule. National Assembly President Jorge Rodriguez, who is a member of Maduro's inner circle, called for the arrest of opposition figure Machado and presidential candidate Edmundo Gonzalez on Tuesday. The country's Public Ministry later clarified that no arrest warrant had been issued for either opposition figure. An energized opposition movement – which overcame their divisions to form a coalition and coalesce around Gonzalez – enjoyed strong polling figures prior to the vote. It had been seen as the ruling establishment's toughest challenge in 25 years. A source from Machado's campaign confirmed to CNN on Thursday that she is currently "sheltered." "I am writing this from hiding, fearing for my life, my freedom," Machado wrote in an opinion editorial published Thursday by The Wall Street Journal. "I could be captured as I write these words." Though Maduro had promised free and fair elections, the process was marred with allegations of foul play – with opposition figures arrested, their key leader Machado banned from running, opposition witnesses allegedly denied access to the centralized vote count, and overseas Venezuelans largely unable to cast ballots. The Carter Center, one of the few independent institutions allowed to monitor the vote, said Tuesday that "Venezuela's electoral process did not meet international standards of electoral integrity at any of its stages and violated numerous provisions of its own national laws." Venezuela's opposition and multiple Latin American leaders have refused to recognize Maduro's victory. The United States had until Thursday been among numerous countries that have called on Venezuelan electoral officials to publish detailed results from the election. Machado says she can prove that Maduro didn't win. "He lost in a landslide to Edmundo González, 67% to 30%," she wrote in the WSJ. "I know this to be true because I can prove it," she claimed. "I have receipts obtained directly from more than 80% of the nation's polling stations," she wrote, claiming to have known Maduro's government "was going to cheat." On Tuesday, Machado posted on X a link to what she says are the results from Sunday's election. CNN has not independently confirmed the election data posted by Machado. "We have known for years what tricks the regime uses, and we are well aware that the National Electoral Council (CNE) is entirely under its control. It was unthinkable that Mr. Maduro would concede defeat," she wrote. CNN has reached out to Maduro's government for comment. The CNE has yet to issue final vote tallies. The opposition leader said "most" of her team were currently in hiding and some, including those in the Argentine Embassy fear an "imminent raid." Machado ended her article by saying it is "now it is up to the international community to decide whether to tolerate a demonstrably illegitimate government." "The repression must stop immediately so that an urgent agreement can take place to facilitate the transition to democracy. I call on those who reject authoritarianism and support democracy to join the Venezuelan people in our noble cause," she said. Deadly protests in Venezuela have seen more than 1,000 people detained, according to Venezuelan authorities. According to Human Rights Watch, there are at least 20 "credible reports" of deaths related to the protests that broke out after the elections results were announced by the CNE. Local NGO Foro Penal has confirmed 11 deaths linked to the protests. Maduro pledged to release all voting data in a private conversation Monday with Brazilian foreign policy envoy Celso Amorim, according to a source with knowledge of the conversation. But on Wednesday, the strongman filed an appeal before the Electoral Chamber of the Supreme Court of Justice to carry out an expert appraisal and certify the results of Sunday's presidential election. He also warned that he would not hesitate to call on the population for a "new revolution" if forced by what he called "North American imperialism and fascist criminals." — CNN