WASHINGTON — Richard Grenell, a close Trump ally who has served numerous roles in the administration, quietly embarked on a pre-election mission last month that was at least partly intended to persuade President Nicolás Maduro of Venezuela to give up power.
Mr. Grenell, a vocal and combative supporter of President Trump’s re-election campaign, met near Mexico City on Sept. 17 with Jorge Rodríguez, a former Venezuelan vice president and close ally of Mr. Maduro, to facilitate a peaceful transition of power, a White House official said.
Had Mr. Maduro agreed to stand down, it could have been a major foreign policy victory for Mr. Trump in the weeks before the election. But there is no evidence that Mr. Grenell’s trip had any effect, and it was not clear why Mr. Maduro, a socialist strongman who has maintained power despite international opposition, would suddenly consider stepping down.
The trip, which was reported by Bloomberg News on Wednesday night, caught the State Department and even some White House officials off guard and created confusion about its purpose.
A person involved in the planning of the trip said that it was intended at least partly to negotiate for the release of American detainees in Venezuela, but the White House official and Mr. Grenell denied that. Under current U.S. policy, officials can negotiate only with Mr. Maduro or his loyalists to discuss the terms of his departure.
Mr. Trump demanded last year that Mr. Maduro resign, and the United States has formally recognized Juan Guaidó, the former leader of Parliament, who heads the country’s popular opposition movement, as Venezuela’s president.
Mr. Trump’s stance, which was at the fore of the international community’s condemnation of Mr. Maduro, won him plaudits among American hard-liners, including among Latino voters in Florida, a pivotal swing state.
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But people close to Mr. Trump questioned his commitment to leadership change; his former national security adviser, John R. Bolton, wrote in a book that published this year that Mr. Trump was impressed by the resilience of Mr. Maduro, who has retained the support of his country’s military.
Mr. Trump was also doubtful of Mr. Guaidó, Mr. Bolton wrote, calling the opposition leader “weak” and referring to him as the “Beto O’Rourke of Venezuela” — a reference to the former Texas congressman, whose unsuccessful bid for the 2020 Democratic presidential nomination did not live up to the high expectations of some in his party.
In July, Mr. Trump traveled to Florida to reaffirm his opposition to Mr. Maduro and other socialist governments in Latin America. He accused his Democratic rival, former Vice President Joseph R. Biden Jr., of supporting “pro-Communist policies” across Latin America in what was seen as an effort to shore up his faltering support among Latinos in the state.
One senior administration official said Mr. Grenell’s meeting with Mr. Rodriguez sidestepped established diplomatic channels to secure a foreign policy victory for the president before the election. The official spoke on the condition of anonymity to discuss the internal discussions.
In the closing months of the presidential campaign, Mr. Trump has sought to showcase his work on the international stage, including freeing American hostages in Yemen, sealing a landmark peace accord between Israel and the United Arab Emirates and Bahrain, and promising to withdraw U.S. troops from Iraq and Afghanistan. He has also been seeking a new nuclear arms deal with Russia.
Mr. Grenell, who had served as Mr. Trump’s ambassador to Germany and the acting director of national intelligence, was involved in another recent effort to broker a major international deal. He was named special envoy for peace talks between Serbia and Kosovo late last year, even though the State Department already had a special envoy to the region.
His brash style and partisan background ruffled feathers among some of those he worked with in the roles.
Mr. Grenell’s trip to Mexico City surprised senior administration officials, including Secretary of State Mike Pompeo. At the State Department, officials scrambled to learn the details of the trip after being asked about it by reporters, with some worrying that it could confuse Mr. Guaidó about the American diplomacy and fuel concerns that the Trump administration was not forthcoming about its strategy.
It also revealed a divide between the White House and the State Department, where officials have long denied that the Trump administration was growing frustrated with Mr. Guaidó and the stalemate in Venezuela as Washington issued blistering economic sanctions against Mr. Maduro’s government and its loyalists.
The White House did not immediately respond to questions about who specifically authorized the trip.
Mr. Maduro has defied demands to leave since a popular revolt in Venezuela in January 2019 against his self-declared victory in widely disputed presidential elections in 2018.
Since then, however, Venezuela’s economy has crumbled under widespread isolation, forcing Mr. Maduro to rely on illicit trade and other assistance from Cuba, Iran, Russia, Turkey and other states that have faced financial punishment or condemnation from the United States as a result.
His government has detained six executives of Citgo — five naturalized American citizens and a permanent legal U.S. resident — since consolidating power in 2017. The Houston-based refining company is a subsidiary of Venezuela’s state-run oil company.
While securing their release could bolster Mr. Trump’s credentials among voters as a deal-maker who brought American hostages and other detainees safely home, it could provoke the ire of hard-liners who do not want to negotiate with Mr. Maduro’s government.
Mr. Grenell declined to comment other than to deny that the trip was related to hostage negotiations.
The White House official also rejected the idea that Mr. Grenell’s trip was intended to negotiate for the release of detainees, instead portraying it as an effort to facilitate Mr. Maduro’s resignation.
“We are very much committed to seeing Maduro leave power and have Juan Guaidó in office,” the official said.
The United States is not the only country that has tried and failed to convince Mr. Maduro to step down. Over the years, negotiations in the Caribbean and Norway, and parties including Spain, the Vatican and the European Union, have worked to resolve the standoff.
As recently as July, Bill Richardson, a senior Democratic former diplomat, met with Mr. Maduro in Caracas, the Venezuelan capital, on a private humanitarian mission. He unsuccessfully sought the release of the Citgo executives and two other Americans who are being held in Venezuela.
But Mr. Grenell’s negotiations with Mr. Maduro’s envoy are certain to unnerve Mr. Guaidó’s opposition efforts. Mr. Guaidó sat in Mr. Trump’s guest box at the State of the Union speech in January and was lauded as “the true and legitimate president of Venezuela” amid speculation that the Trump administration had lost patience with the impasse.
A spokesman for Mr. Guaidó’s ambassador to Washington declined to comment on Wednesday night.