A security guard patrols the area where the Summit of the Americas will take place in Lima, Peru. (Ivan Alvarado/Reuters)

At the Summit of the Americas, the elephant will not be in the conference room.

President Trump has bowed out of the summit, a periodic gathering of hemispheric leaders that opens Friday in Lima, Peru, with aides saying he needs to monitor the crisis in Syria. He has passed the baton to Vice President Pence.

Trump is deeply unpopular in the region. He has lambasted Mexico over drugs and illegal immigration, reversed a thaw in relations with Cuba, and threatened military action against Venezuela. Without him, the gathering will probably lose a frisson of drama.

This is the first time in the nearly quarter-century history of the meeting that a U.S. president will not attend. But the ­last-minute change of plans may be one more jolt for a two-day summit that was already particularly unusual, a microcosm of the tumult sweeping the Western Hemisphere.

The theme for the summit is the fight against corruption and need for transparency, but it’s taking place at a time when Latin America is a study in how corruption has spread. Scandals have engulfed an ever-growing roster of regional leaders, gut-punching their approval ratings, forcing some out of office and putting others behind bars.

“I would call this the surreal summit,” said Richard E. Feinberg, who helped organize the first Summit of the Americas, in 1994, and is a Latin America expert at the University of California at San Diego. “The whole thing is rather bizarre.”

The original host, Peruvian President Pedro Pablo Kuczynski, stepped down in disgrace on March 21 after lawmakers claimed he misrepresented his financial relationship with Odebrecht, a Brazilian construction company. That firm is at the heart of the “Car Wash” scandal that began in Brazil in 2014 and has implicated scores of political and business leaders across Latin America.

In Brazil, former president Luiz Inácio Lula da Silva ended a dramatic two-day standoff with authorities on Saturday, turning himself in to face a 12-year sentence on corruption charges. Lula, who was planning to run for reelection, is by far the biggest figure to fall in the scandal.

Another president — Nicolás Maduro of Venezuela, who was not invited because of his government’s democratic shortcomings — had threatened to crash the summit. But this week, he said he would “stay home with the Venezuelan people.”

“In truth, the Summit of the Americas is a waste of time,” Maduro said Tuesday.

As the U.S. representative, Pence is set to face the leaders of a number of nations that have uneasy relationships with Trump.

Earlier this week, Mexican President Enrique Peña Nieto launched a review of all bilateral cooperation with the United States, after several stinging Trump tweets accused Mexico of failing to stop immigrants from crossing illegally into the United States.

Trump has launched a renegotiation of NAFTA and ordered National Guard troops to reinforce the border. Peña Nieto had canceled a trip to Washington earlier this year amid an ongoing dispute about whether Mexico would pay for a giant border wall, and some in his government expected the summit could be a place for the two presidents to talk. Now that won’t happen.

While Trump won’t attend the summit, administration officials emphasized that the U.S. delegation will nonetheless include Commerce Secretary Wilbur Ross and the president’s daughter and adviser, Ivanka, who will unveil an “initiative to propel women’s economic empowerment in the region,” as she told reporters on a conference call arranged by the White House on Wednesday. Administration officials declined to release details on the new program.

“We are sending a very strong delegation down,” a senior administration official said on the call, speaking under ground rules that he was not further identified. “We expect to see great things as a result of it.”

But the summit could become a venue to air the discontent toward the Trump administration that is roiling the region.

A Gallup poll released this year found that Trump’s approval rating in Latin America was just 16 percent, dramatically different from President Barack Obama’s rating in the first year of his presidency. Latin American citizens have expressed revulsion at Trump’s rhetoric, such as his reported vulgar comment about immigrants from Haiti, El Salvador and Africa. Trump has moved to end programs that protect immigrants from deportation, such as temporary protected status, which benefited some 200,000 Salvadorans and 60,000 Haitians.

Trump has threatened other Latin American countries on issues including immigration, trade and drugs. This month he warned that aid to Honduras might be cut because of a caravan of would-be immigrants heading to the U.S. border. Last year, he said he “seriously considered” decertifying Colombia as a partner in the war on drugs because of surging cocaine production. While many Latin American governments have backed Trump’s decision to increase sanctions on Venezuela, the president sparked a backlash in the region when he said that he would not “rule out a military option” to confront that country’s government.

The situation in the region is so troubled — and its relationship with the Trump administration so fraught — that some analysts even suggested the summit should be scrapped. Even though it’s moving forward, experts predict it will fail to seriously deal with deep-seated problems.

When it comes to corruption, “they’re going to have to finesse how do they talk about it seriously and keep a straight face,” said Michael Shifter, president of the Inter-American Dialogue, a Washington think tank. “It’s a good topic, but not a good political moment for it.”

Feinberg, who has attended six of the seven summits that have occurred since 1994, said the hemisphere’s leaders will probably announce some commitments similar to those made in a 1996 agreement, the Inter-American Convention Against Corruption. This, he said, raises the question: “In the last 22 years, what have you done and why should we believe you now?”

Accusations of fraud tainted the presidential election in Honduras in January, and Maduro’s government in Venezuela has repeatedly flouted democratic norms. Peña Nieto’s administration in Mexico has been battered by scandals involving government spying, police collusion with drug traffickers, and allegations that a government contractor built a home for the president and his wife.

But the Odebrecht scandal remains the most blatant symbol of the sludge that sloshes through Latin American politics.

In Colombia, former senator Otto Bula was detained last year, accused of receiving $4.6 million in exchange for securing Odebrecht a contract for a highway. Colombian President Juan Manuel Santos has acknowledged that his 2010 election campaign received illegal payments from Odebrecht, but he said he had been unaware of the contributions.

In Argentina this week, a judge charged Julio De Vido — the former planning minister of ex-president Cristina Fernández de Kirchner — of wrongdoing in the awarding of multimillion-dollar contracts to Odebrecht. Fernández de Kirchner, meanwhile, is fighting an indictment for allegedly covering up Iranian involvement in the 1994 bombing of a Jewish community center in Buenos Aires.

Pence’s office issued a statement Tuesday saying that he looks forward to “working with our close allies in Latin America to collectively hold undemocratic actors in the region accountable for their actions.”

Among the Trump administration’s priorities in the region is curbing socialist Venezuela’s slide toward authoritarianism. Maduro is seeking a new mandate next month in elections that the opposition plans to boycott, citing the banning of several potential contenders and fears of fraud.

But now that Kuczynski, a leading critic of the Maduro government, has resigned, some expect the temperature will be lowered on the Venezuela issue at this summit.

The U.S. government also may press Colombia on a jump in the cultivation of coca — the main ingredient in cocaine. But just as notable as what will be discussed are those issues expected to be on the back burner.

The initial Summit of the Americas in 1994 was all about free trade. But Trump has threatened to raise tariffs and renegotiate or scrap trade pacts, saying many are unfair to U.S. workers.

“This is one of the most unusual summits I’ve ever seen,” said Eric Farnsworth, who worked on Latin America issues in the Clinton administration and is now Washington director of the Americas Society/Council of the Americas, a regional trade and dialogue promotion group. “The anti-corruption element has been thrown out the window by recent events. . . . But it’s also significant that the dog isn’t barking on the economic agenda. Where are the talks on trade here?”