OTTAWA -- Justin Trudeau's arrival Tuesday in Cuba -- the first official visit by a Canadian prime minister in almost two decades -- is the first step in the Liberal government's week-long bid to boost Canadian trade, investment and engagement in the region.

The visit is a necessary and symbolic stop en route to Argentina and Peru because Cuba is a political and diplomatic gateway to the Americas, said Allan Culham, Canada's former ambassador to the Organization of American States.

"A visit to Cuba is a rite of passage in the Americas," Culham said. "You can't have any credibility in the Americas without having gone to Cuba."

The Prime Minister's Office has publicly said the visit would focus on trade and investment, but the context of those talks has changed in the last week with U.S. president-elect Donald Trump's tough stances on free trade.

Thanks to places like Argentina, where liberal democracy is being embraced, Canadians may be able to play a more influential role in South America, said Culham -- particularly at a time when the U.S. is turning dramatically inwards.

"This is a real opportunity for us on the hemispheric stage to make a difference both politically and practically."

Canada's reputation in South America has taken a hit in the last decade from concerns about the environmental and social effects of Canadian mining operations, said John Kirk, a professor in the department of Spanish and Latin American studies at Dalhousie University in Halifax.

"We have done a dismal job," Kirk said.

"I've got students in several places in Latin America that have taken the maple leaf off the backpack precisely because of the role of (former prime minister) Stephen Harper."

In Cuba, Trudeau is scheduled to meet Tuesday with president Raul Castro shortly after his arrival in Havana before attending a state dinner.

There is no scheduled meeting with Fidel Castro, the former Cuban leader who was an honorary pallbearer at Pierre Trudeau's funeral in 2000.

Given his health, the elder Castro rarely meets with world leaders in Cuba. But Trudeau is well-positioned to be granted a rare audience, said Culham, given his family's ties to the Castros and the fact Canada is one of only two Western countries that didn't sever diplomatic ties with the island nation when the U.S. did so in 1961.

Trudeau is also scheduled to meet Wednesday with students at the University of Havana and with local civil society groups.

On Thursday, he's scheduled to meet with Argentina's new president, Mauricio Macri, before spending the weekend in the Peruvian capital of Lima at the APEC leaders' summit, where he's expected to speak.

The talk in the hallways is likely to be about Trump's plan to pull out of the Trans-Pacific Partnership, a 12-nation trade deal that would have involved countries comprising 40 per cent of the global economy, including Canada.

Trump's pledge and U.S. President Barack Obama's decision to not push Congress to ratify the deal before his term ends leaves Trudeau and other leaders to pick up the pieces.