LIMA, Peru — Cuban President Raul Castro joined a steadily growing list of leaders who have followed U.S. President Donald Trump in choosing to send a surrogate to what is shaping up into a decidedly low-key Summit of the Americas.

The gathering of Western Hemisphere leaders kicked off Friday in Peru without the presence of at least five presidents besides Trump — and the list of canceled RSVPs could grow.

Castro had never officially confirmed his attendance but he was widely expected to show up to bid farewell to regional allies as he prepares to step down from the Cuban presidency in a week's time. Instead he sent his Foreign Minister Bruno Rodriguez to lead the Cuban delegation.

Nicaragua's President Daniel Ortega was also widely expected to snub the event in solidarity with fellow leftist Nicolas Maduro of Venezuela, who had his invitation withdrawn.

Meanwhile, the presidents of El Salvador, Guatemala and Paraguay all announced they will be staying home, saying they need to attend to pressing domestic matters and will send alternates instead. Ecuador's president showed up but then quickly returned home after three journalists kidnapped by holdout Colombian rebels were killed.

Analysts said the shrinking list of presidential attendees could be indicative of declining U.S. influence in the hemisphere. Trump is the first U.S. president to ditch the event, which was started by President Bill Clinton in 1994 as a way to assert American trade influence in the region. Trump canceled in order to manage the U.S. response to an apparent chemical weapons attack on civilians in Syria.

"It appears that in most of these situations, there are specific and unique reasons for heads of state not to attend," said Matt Clausen, who is in Lima as head of the Washington Office on Latin America. "What has changed since President Trump pulled out is the calculus about the overall importance of the summit."

And it isn't just a rising roster of no-shows that make this year's summit of dubious importance: Presidents from three of Latin America's most populous nations who are attending are all slated to leave office within the next 12 months.

The summit was initially started to promote democracy and free trade in the Americas, but in recent years both topics have become testy subjects. Instead the summit has become a stage for awkward encounters between leftist leaders and their northern counterparts.

Protesters led by soccer legend Diego Maradona burned an effigy of President George W. Bush to protest the U.S.-led invasion of Iraq at the 2005 summit in Argentina. Four years later, the late Venezuelan leader Hugo Chavez famously gave then President Barack Obama a copy of a classic leftist book, "The Open Veins of Latin America," detailing the history of U.S. military interventions in the region.

Another key summit moment came in 2015 when Obama and Castro shook hands while in Panama City four months after the U.S. announced it would renew diplomatic relations with the communist island.

Things have changed dramatically since that handshake.

The Trump administration has rolled back many of Obama's overtures to open travel and commerce with the island and withdrawn most of its diplomats in Cuba over mysterious "sonic attacks" in Havana. Many feared that if Trump had showed up at this year's summit, his harsh anti-immigrant rhetoric and threats to pull out of regional trade deals would have generated tense encounters.

Vice President Mike Pence is expected to use the trip to promote trade and urge regional partners to further isolate Venezuela's government. The region has been grappling with how to respond to Maduro's increasingly autocratic rule, along with a crippling economic crisis and an exploding tide of migration.

Maduro was barred from this year's meeting over his plans to hold a presidential election that most of the opposition is boycotting and that many foreign governments are decrying as a sham. The Venezuelan president said Trump's cancellation was another sign the U.S. still views Latin America as Washington's backyard.

Several of Venezuela's most prominent opposition leaders are gathered in Lima, hoping to help build a forceful region-wide response.

Just before the summit was set to get underway Friday, Trump signaled that he might reopen talks on a Pacific Rim trade deal that he pulled the U.S. out of after taking office.

Without mentioning Trump's policy reversal on the Trans Pacific-Partnership, Canada's Prime Minister Justin Trudeau celebrated that several countries in the hemisphere including host Peru — one of the most-open economies in Latin America — have embraced his government's vision of beneficial free trade agreements.

Mexico's President Enrique Pena Nieto also urged the Trump administration to join the accord.

"There's a door open for the U.S. to rethink and eventually reconsider its position," he told a group of business leaders.