(CNN) – US government officials are still rushing to Confirm attendance and prepare announcements What President Joe Biden will do just one week before he hosts Western Hemisphere leaders in Los Angeles for the Summit of the Americas.

It is a rare last-minute attempt to salvage what officials once described as a high-priority event for relations in America’s neighborhood. The absence of the most important leaders — especially the president of Mexico, who is threatening a boycott — threatens to undermine the meeting, even as Biden and his team try to make progress on politically sensitive issues, such as immigration on the US southern border. and economic growth.

Officials say the summit will go ahead and have played down any concerns about who might attend. They have begun to finalize Biden’s agenda and program for the meeting, which will last several days.

Even before it began, though, organizational wrangling at the summit revealed rifts in an area Biden had hoped to reassert American leadership.

Next week’s Summit of the Americas will be the ninth gathering of countries in the region and the first time the United States has hosted such a gathering since it opened in Miami in 1994. The grouping, which stretches from Canada in the north to Chile in the south provides an opportunity to strengthen ties at a time of historic migration and as China is working tirelessly to make progress in the region.

Both issues are of vital importance to Biden, who has raised competition with Beijing as the main challenge for the coming decades and fought to control illegal border crossings.

But the success of the summit may depend on who attends.

Last month, President Andres Manuel Lopez Obrador He said That Mexico’s participation will not be confirmed until the United States invites all countries of the hemisphere, arguing that no country should be excluded from the top.

US officials have repeatedly said that authoritarian governments in Cuba, Nicaragua and Venezuela They will not be invited to the summit because of their anti-human rights record. But Mexico and other countries in the region have closer relations with those countries and described the decision as exclusionary.

Senior officials in the Biden administration on Wednesday dismissed concerns about attendance at the upcoming Summit of the Americas, highlighting instead the ongoing coordination between countries to address regional issues.

“We still have to make some final considerations, but we will be announcing the final guest list soon,” said Juan Gonzalez, senior director for the Western Hemisphere at the National Security Council, adding, “We haven’t focused too much on the guest list.” Who is invited, who is not invited and really more on the results we want to achieve at the summit.”

Kevin O’Reilly, the national coordinator for the Summit of the Americas, told lawmakers last week that neither Venezuela nor Nicaragua were invited, but he turned to the White House to see if anyone from the Cuban regime had been invited.

“This will be a decision for the White House to make,” O’Reilly told Senator Marco Rubio, who asked about the guest list.

The White House was considering the possibility of Invite a Cuban actor, although no decision has yet been confirmed. Cuba was not invited to the first editions of the Summit of the Americas, in the 1990s, but participated in the later editions. President Barack Obama then faced a historic handshake and met Raul Castro at the summit organized by Panama in 2015.

The White House refused to reveal the list of invitees, even in the days before the summit began. After insisting on whether poor attendance would hamper the impact of the summit, Gonzalez said the meeting would be “well attended” and that the relationship with Mexico “will remain positive.”

The White House shrugged off questions about why the details were finalized a week before the summit began.

“I think if you’ve followed this administration for the last year and a half, the week is not going to be the eleventh hour when it comes to how it’s going. So that’s the age for us as the White House,” he said Wednesday. Secretary Karen Jean-Pierre.

However, he appears to have acknowledged that questions about aid have overshadowed some of the summit’s goals.

“I know there are always questions about invitations, there are always questions about who is coming and who won’t, but we also have to talk and focus on what the point of this meeting is,” he said.

The ebb and flow of summit attendance indicates changing dynamics in the Western Hemisphere, with some countries distancing themselves from the United States.

Some US officials have played down the reluctance of some leaders to attend as an attempt to appeal to their political base and caution against interpreting such decisions as a sign of waning US influence.

The administration has worked hard to maintain American influence in the region, including through recent high-profile visits by First Lady Jill Biden and Vice President Kamala Harris.

Former Senator Christopher Dodd, who serves as a special advisor to the summit, traveled to South America and met with officials from Brazil, Chile and Argentina. After Dodd’s visit, the Brazilian Foreign Ministry confirmed that President Jair Bolsonaro will attend the summit and plans to hold his first bilateral meetings with Biden.

Relations between the United States and Brazil have been strained since former President Donald Trump, a political ally of Bolsonaro, failed in his bid for re-election. The Brazilian president was one of the last world leaders to congratulate Biden after the 2020 US election and publicly criticize US pressure to curb increasing deforestation in the Brazilian Amazon.

He was initially skeptical about traveling to Los Angeles for the summit and complained that Biden ignored him when they met at the G-20 summit last year. But he agreed to attend when he was assured that he would not be limited to one photo.

Dodd has held similar conversations with other leaders in the region, including lengthy talks with Lopez Obrador, although he has yet to receive a commitment from the Mexican leader to attend.

Even assistance from countries working directly with the US government – more specifically with Harris – remains in question. The leaders of Honduras, Guatemala and El Salvador have yet to commit to attending next week’s summit, although Harris has worked to develop ties in the region, including attending the president’s inauguration in Honduras in January. Harris spoke with Honduran President Xiomara Castro last week, but did not mention the summit in the conversation.

Other countries, such as Chile and Argentina, have criticized Washington’s decision to exclude certain countries.

Latin American countries are discussing aid among themselves, according to a senior Guatemalan official.

“Each country has its own decision-making process and arguments that say we are going or not going,” the senior Guatemalan official said. Guatemala is expected to send a delegation to the summit, although it is unclear if the president will attend.

The Biden administration is preparing a declaration on immigration for states to sign that provides a framework for protecting immigrants.

“This announcement will allow us to focus on enhancing the stability of the communities that host immigrants, assisting those communities and the immigrants that host them, and ensuring things like access to legal documents and public services,” he told reporters on Wednesday. Press Brian Nichols, Assistant Secretary of State for Western Hemisphere Affairs at the State Department.

Officials also expect results in boosting economic growth, coordinating recovery from the epidemic, and combating climate change.

Democratic Representative Joaquin Castro expressed optimism about the summit, even if some countries did not attend. “We can make it work,” he told CNN. “We have a daily relationship with these countries, but the summit is an opportunity for countries to come together and plan.”

But Castro added that countries that have not yet committed will be “missed” if they do not attend.

With no guarantees of who will attend, it is not clear what weight the summit pronouncements will carry.

Traveling across Latin America last week, First Lady Jill Biden — who will join her husband in Los Angeles for the opening ceremony and leaders’ dinner — said she received assurances that countries she visited, including Ecuador, Panama and Costa Rica, would attend the Summit of the Americas.

The first lady ruled out the possibility of a boycott.

“I’m not worried,” she said. “I think they will come.”