Mexico’s leftist President Andrés Manuel López Obrador announced Monday that he is skipping the Summit of the Americas, following through on his threat to boycott the upcoming meeting if the White House refused to invite officials from all nations in the Western Hemisphere.

The Biden administration’s decision to bar the governments of Cuba, Nicaragua, and Venezuela from this week’s gathering in Los Angeles was made final on Sunday.

Unnamed sources familiar with deliberations between Washington officials and their Latin American and Caribbean counterparts, including those in Mexico, said that U.S. President Joe Biden’s long-anticipated move was “based on concerns about the lack of democracy and respect for human rights in the three countries,” Bloomberg reported.

However, the White House is reportedly considering a role for Juan Guaidó—an unelected and unpopular right-wing opposition figure who participated in a failed, Trump-backed bid to overthrow elected Venezuelan President Nicolás Maduro in 2019—at a virtual side event.

Washington does not officially recognize Maduro as the legitimate leader of the South American country even though he was re-elected last year in a contest that U.S. legal observers called fair. Instead, the U.S. recognizes Guaidó as interim president, and Biden previously invited the Venezuelan coup leader to his administration’s so-called Summit for Democracy in December.

In addition to Maduro, the U.S. is excluding Nicaraguan President Daniel Ortega, whose 2021 re-election Biden called fraudulent, from the Summit of the Americas.

According to U.S. officials, the Biden administration decided against inviting a lower-ranking government representative to attend in place of Cuban President Miguel Díaz-Canel, who said last month that he would not travel to Los Angeles even if invited due to the White House’s “brutal” pressure campaign to make this week’s event non-inclusive.

Cuba participated in the 2015 meeting in Panama and the 2018 meeting in Peru, which former U.S. President Donald Trump skipped.

Despite Democratic lawmakers’ pleas and Biden’s own campaign pledge to reverse Trump’s “failed” approach to Cuba—which included implementing more than 200 punitive policies following Obama-era efforts at normalization—the White House has imposed additional sanctions in recent months, intensifying Washington’s 60-year embargo on the Caribbean island.

Among other officials in the hemisphere, far-right presidents Jair Bolsonaro of Brazil and Iván Duque of Colombia are expected to attend the Summit of the Americas, which begins Monday and ends June 10.

Like López Obrador, however, Honduras’ socialist President Xiomara Castro will not be making the trip to Los Angeles. Her decision to stay home was announced Sunday.

Mexican Foreign Minister Marcelo Ebrard and Honduran Foreign Minister Eduardo Enrique Reina are expected to fill in, but the absence of multiple Central American presidents is likely to complicate Biden’s agenda, which reportedly includes crafting an agreement to reduce and manage undocumented migration as well as discussions of regional economic, health, and food security issues exacerbated by rising inequality and the fossil fuel-driven climate crisis.

Aileen Teague, a non-resident fellow at the Quincy Institute, argued last month that “the Biden administration will lose political capital if it allows its growing tendency to divide the world into ‘democratic’ friends and ‘authoritarian’ states to dictate the invitation list for a forum that is much larger than Washington’s professed policy objectives.”

The stated focus of the Summit of the Americas is to commit to “concrete actions that dramatically improve pandemic response and resilience, promote a green and equitable recovery, bold strong and inclusive democracies, and address the root causes of irregular migration.”

John Kirk, professor emeritus of Latin American Studies at Dalhousie University in Canada, argued last week that “for a summit that aims to ‘dramatically improve pandemic response,’ it seems odd to exclude Cuba—the only country in Latin America to have developed its own Covid vaccines, to have sent thousands of medical professionals abroad to help people during the pandemic, and to have fully vaccinated 96% of the population. (Latest figures show fewer than 70 Covid cases per day).”

“In terms of their role abroad, some 5,000 Cuban specialists worked in 42 countries on anti-Covid missions,” Kirk continued. “As the prime minister of Dominica, Roosevelt Skerrit explained: ‘Here in the Caribbean if the support of Cuban doctors was to be removed from the health system of all the countries that are members of Caricom [the Caribbean Community], these would collapse.’”

“Cuba has one of the best public health systems in the Americas,” wrote Kirk. “Given these successes, and its program of international medical support, why not at least listen to its successful approach to the pandemic?”