Vice President Joseph R. Biden met Wednesday at the White House with the spouse of a jailed Venezuelan opposition leader just a week after the South American nation’s president accused Mr. Biden of actively helping to plot a coup against him.
Sources familiar with the meeting said Lilian Tintori, whose husband Leopoldo Lopez was arrested last February in Caracas, pressed Mr. Biden and others in the Obama administration to be more aggressive in condemning human rights violations in Venezuela.
Mr. Biden’s office confirmed the meeting had taken place, saying in a statement that the goal was to “underscore” the administration’s “commitment in promoting human rights around the world.”
The meeting comes as political tensions have spiked between Washington and Caracas. The Obama administration last week imposed new visa restrictions on Venezuelan officials believed to be associated with human rights abuses as well as a crackdown on political opposition.
Venezuelan President Nicolas Maduro, the protege and successor of the late socialist President Hugo Chavez, a fierce critic of Washington, responded to the move by publicly asserting last week that Mr. Biden was plotting to overthrow him — a claim the White House dismissed as “patently false.”
Mr. Maduro said Mr. Biden was trying to foment his ouster during a Caribbean energy summit the U.S. vice president hosted last month in Washington. He claimed the U.S. vice president had told regional heads of state attending the summit that the government in Caracas was near collapse, and they should abandon it.
The accusation came as a surprise, since Mr. Maduro and Mr. Biden had been photographed while shaking hands and expressing mutual interest in warmer relations during an impromptu meeting a month earlier in Brazil.
While the U.S. remains a significant buyer of Venezuelan oil, the recent developments have cast a shadow over hopes that the two nations might improve their long-rocky relationship in light of the Obama administration’s recent push for a thaw in relations with Cuba, Caracas’ closest strategic and ideological ally.
At a minimum, Mr. Biden’s meeting Wednesday with the spouse of one of Mr. Maduro’s main political rivals suggests the Obama administration feels emboldened to take a stand on human rights in Venezuela.
Whether other Latin American leaders will join the U.S. is an open question. One regional analyst, who spoke on condition of anonymity, argued the U.S. has a long history of subversively meddling in Venezuela’s internal affairs, and that the Obama administration is presently “isolated in the region in its support for the Venezuelan opposition.”
Widespread regional rejection of Washington’s policy toward Venezuela “somehow just never makes it into the U.S. news,” the analyst said.
Other regional experts have argued that where Chavez once drew praise for oil profits to underwrite his socialist agenda in Venezuela, Mr. Maduro has had to resort to more coercive tactics to retain power with oil prices plummeting.
Mr. Maduro won a razor-thin victory in a special election in April 2013, a month after Chavez’s death. But Venezuela’s opposition, a largely upper-class movement notoriously fractured during the Chavez reign, was determined to make a stand, refusing to recognize the Maduro victory and staging massive anti-government rallies in Caracas.
At first it appeared Mr. Maduro might weather the political storm. But Chavez left huge shoes to fill, and demonstrations in Caracas soon spiraled out of control, resulting in the deaths of at least 43 people, including anti-Maduro demonstrators, his supporters and security officials.
The new president then began drawing the ire of international human rights groups by cracking down on the opposition. Most notably, his government arrested Mr. Lopez, the 43-year-old former mayor of Caracas’ affluent Chacao district, who had emerged as a major protest leader calling for Mr. Maduro’s ouster.
The year since has seen Mrs. Tintori, Mr. Lopez’s wife, plead with international leaders to demand his release. When she met with Mr. Biden Wednesday, she had with her two other Venezuelan human rights advocates, including the brother of Juancho Montoya, a longtime supporter of the pro-Chavez — “Chavista” — movement in Venezuela who was killed during last year’s protests in Caracas. Rosa Maria Orozco, the mother of Geraldin Moreno Orozco, who was allegedly shot in the face at point-blank range and killed by Venezuelan government forces, was also part of the meeting.
Mr. Lopez has been held in a military-run prison since shortly after handing himself over to security forces last February to face charges of arson, terrorism and homicide related to the deaths that occurred during the protests that shook the nation last year.
Human rights lawyers claim the charges are bogus.
“The detention of Lopez is arbitrary and in violation of international law,” wrote Jared Gensler, a U.S.-based attorney representing Mr. Lopez, in a white paper on the case. “Specifically, the detention is arbitrary because Lopez was imprisoned for exercising his rights to freedom of expression, peaceful assembly, and right to take part in public affairs.”
In an interview with The Times Tuesday, Mrs. Tintori said her husband has become the symbolic face of dozens of jailed opposition activists in Venezuela, and of a movement that won’t die until there is “clear justice, a clear rule of law and human rights for all people” in the nation.
Mrs. Tintori and her fellow activists met Tuesday in Washington with Organization of American States Secretary General Jose Miguel Insulza as part of a wider effort to convince regional leaders to put pressure on the Maduro government ahead of an annual Summit of the Americas meeting to be held April in Panama City.
At a press conference following the Biden meeting Wednesday, Mrs. Tintori said she was in Washington to “send a clear message to President Maduro, and to the rest of the world … we cannot sit here and remain silent while so many suffer.”
She added that she and the others traveling with her were wary of how they’ll be received upon return to Venezuela. “I don’t know what is going to happen when we try to enter back into the country,” she said.
• Christopher White contributed to this article.