Biden and Trudeau met one-on-one before a three-way meeting with Mexican President Andres Manuel Lopez Obrador at the Mexico City summit.
The US and Canadian leaders' warmth during a brief appearance before reporters at the start of their talks stood in stark contrast to a more brusque exchange a day earlier between Biden and Lopez Obrador, who had complained of "abandonment'' and "disdain'' for Latin America.
Biden told Trudeau, "What we should be doing, and we are doing, is demonstrating the unlimited economic potential that we have when we work together in the hemisphere, and to help the entire hemisphere.''
All three world leaders were to discuss migration, trade and climate change as they look to mend tensions that have divided the continent.
The three-way gathering is held most years, although there was a hiatus while Donald Trump was US president. It's often called the ``three amigos summit,'' a reference to the deep diplomatic and economic ties among the countries.
However, the leaders have found themselves at odds, especially as they struggle to handle an influx of migrants and to crack down on smugglers who profit from persuading people to make the dangerous trip to the United States.
In addition, Canada and the US accuse Lopez Obrador of violating a free trade pact by favoring Mexico's state-owned utility over power plants built by foreign and private investors.
Meanwhile, Trudeau and Lopez Obrador are concerned about Biden's efforts to boost domestic manufacturing, creating concerns that US neighbors could be left behind.
The key takeaways from the summit revolve around better connections among the three nations and a shared goal of a stronger North America on energy and in particular semiconductors, climate and a pledge to cut methane emissions, an agreement to manage large waves of migrants coming to the region and a more cohesive regional strategy on dealing with future pandemic-related health threats.
The dynamics as the Biden-Trudeau talks opened could not have been more different than for the Biden-Lopez Obrador talks.
During that meeting, the Mexican leader challenged Biden to improve life across the region, telling him that "you hold the key in your hand.''
"This is the moment for us to determine to do away with this abandonment, this disdain, and this forgetfulness for Latin America and the Caribbean,'' Lopez Obrador said.
Biden responded by pointing to the billions of dollars that the United States spends in foreign aid around the world.
At the start of Tuesday's Biden-Trudeau meeting, the leaders spoke familiarly and with optimism. Trudeau called the US president "Joe" and Biden joked with Trudeau, after the Canadian leader had delivered a statement to reporters in English and French, that he should have paid more attention in his college French classes.
The White House said in a statement that the leaders discussed the war in Ukraine and ``the generational opportunity to strengthen supply chains for critical minerals, electric vehicles, and semiconductors and to unleash the full economic potential of our shared continent.'' The US administration also announced that Biden will make his first visit to Canada as president in March.
"There's a lot of reasons to be optimistic, especially for those of us in our countries,'' Trudeau said. "But it's going to take a lot of work, something neither you or I or most our citizens have ever been afraid of.''
Biden told his counterpart: "Together, I think we're achieving some really significant things. You've always been there whenever I've called.''
Biden and Lopez Obrador haven't been on particularly good terms for the past two years. The Mexican leader made no secret of his admiration for Trump, and last year he skipped a Los Angeles summit of the Americas because Biden didn't invite the authoritarian leaders of Cuba, Venezuela and Nicaragua.
However, there have been attempts at a thaw. Biden made a point of flying into the new Felipe Angeles International Airport, a prized project of the Mexican president even though it's been a source of controversy.
The airport, which is expected to cost $4.1 billion when finished, is more than an hour's drive north of the city center, has few flights and until recently lacked consistent drinking water.
However, it's one of the keystone projects that Lopez Obrador is racing to finish before his term ends next year. The US president is scheduled to depart from Mexico City International Airport on Tuesday evening.
The US and Mexico have also reached an agreement on a major shift in migration policy, which Biden announced last week.
Under the plan, the US will send 30,000 migrants per month from Cuba, Nicaragua, Haiti and Venezuela back across the border from among those who entered the US illegally.
Migrants who arrive from those four countries are not easily returned to their home countries for a variety of reasons.
In addition, 30,000 people per month from those four nations who get sponsors, background checks and an airline flight to the US will be able to work legally in the country for two years.
The number of migrants crossing the US-Mexico border has risen dramatically during Biden's first two years in office. There were more than 2.38 million stops during the year that ended Sept. 30, the first time the number topped 2 million.
Biden said he and Trudeau would discuss "how we can try to help stabilize Haiti."
Canada is weighing whether to lead an international mission to Haiti to help solve the ongoing humanitarian and security crisis.
Haitian Prime Minister Ariel Henry and the country's Council of Ministers sent an urgent appeal Oct. 7 calling for "the immediate deployment of a specialized armed force, in sufficient quantity'' to stop the crisis caused partly by the "criminal actions of armed gangs.'' But more than three months later, no countries have stepped forward.