WASHINGTON -- Reviving three-way North American summitry after a five-year break, President Joe Biden on Thursday joined with the leaders of Canada and Mexico to declare their nations can work together and prove "democracies can deliver" even as they sort out differences on key issues.

But as Biden, along with Canadian Prime Minister Justin Trudeau and Mexican President Andres Manuel Lopez Obrador, spoke of their mutual respect, the three leaders also found themselves dealing with fresh strains on trade, immigration, climate change and other matters.

"We can meet all the challenges if we just take the time to speak to one another, by working together," said Biden, who hosted the North American neighbors for what had been a near-annual tradition in the decade before President Donald Trump came to office.

It was a day of full-on diplomacy requiring careful choreography as Trudeau and Lopez Obrador each met separately with Biden and Vice President Kamala Harris before gathering for a three-way conversation in the East Room featuring a language mix of English, French and Spanish.

As they played up the closeness of the alliance, points of tension were also clear.

President Joe Biden meets with Mexican President Andres Manuel Lopez Obrador in the Oval Office of the White House on Thursday in Washington.Susan Walsh ~ Associated Press

They include differences between Washington and Ottawa over proposed tax incentives benefiting U.S. electric car auto manufacturers, frustration from Lopez Obrador the U.S. isn't moving to issue more temporary work visas even as American businesses complain they suffer from a worker shortage, and disappointment by the U.S. and Canada that Mexico is not moving faster to address climate change.

Biden met first with Trudeau, calling the U.S.-Canada relationship one of the easiest in the early going of his presidency.

But as they sat down for talks, the president also confirmed their differences over proposed electric vehicle tax incentives in his massive social services and climate bill.

"We're going to talk about that," Biden said. "It hasn't even passed yet in the House."

The provision in Biden's proposed spending plan would offer American consumers a $7,500 tax credit if they buy electric vehicles through 2026. The following year, only purchases of electric vehicles made in the U.S. would qualify for the credit. The base credit would go up by $4,500 if the vehicle was made at a U.S. plant that operates under a union-negotiated collective bargaining agreement.

Canadian Deputy Prime Minister Chrystia Freeland on Wednesday called the incentive a clear violation of an updated trade agreement among the three countries that aimed to protect U.S. jobs and products made in North America.

The union provision has also sparked pushback from some non-union shops and U.S. lawmakers. Still, White House press secretary Jen Psaki said that Biden "is pretty committed to the bill providing good-paying union jobs."

Trump had an icy relationship with Lopez Obrador's predecessor, pressing Enrique Pena Nieto to never publicly say that Mexico wouldn't pay for a southern U.S. border wall.

But Lopez Obrador appeared to reach a one-issue understanding with Trump: Mexico slowed the flow of Central American migrants trying to reach the U.S. border, and Trump often appeared to turn a blind eye to just about every other facet in the complicated relationship.

Lopez Obrador offered warm words for Biden when they appeared before the cameras Thursday. The two leaders discussed Mexico's relations with the U.S. under Abraham Lincoln and Franklin D. Roosevelt before the portraits of both that Biden has displayed prominently in the Oval Office.

The Mexican president praised Biden for treating his government with respect, something he noted has not always been a given in the two countries' long history and for including funding in his spending bill to overhaul the immigration system. But he also alluded to his desire to see the U.S. move quickly on temporary visas.

Lopez Obrador has mentioned on multiple occasions his interest in the U.S. government expanding its work visa program so more Mexicans and Central Americans can fill the demand for labor in the U.S. The temporary workers in turn could have access to the higher pay they seek in the U.S. without becoming part of the illegal immigration flow.

"Why not study the workforce demand and open the migratory flow in an orderly manner?" Lopez Obrador said.

Thursday's meetings at the White House marked the first trilateral get-together for North American leaders since a June 2016 gathering of Trudeau, Barack Obama and Enrique Pena Nieto in Ottawa. The tradition of three-way meetings started when George W. Bush played host to Mexico's Vicente Fox and Canada's Paul Martin in 2005 at his ranch in Texas.

Mexico's priorities heading into the summit were to obtain concrete advances on immigration and more equitable access to COVID-19 vaccines.

The U.S. and Canada have expressed frustration that Lopez Obrador has failed to get on board with global efforts to curb climate emissions. The Mexican president skipped this month's U.N. climate summit in Glasgow and has accused elite nations of demonstrating "hypocrisy" when it comes to environmentalism.

Trudeau and Biden were also expected to discuss the future of an oil pipeline that crosses part of the Great Lakes and is the subject of rising tension over whether it should be shut down. Biden is caught in a battle over Enbridge's Line 5, a key segment of a pipeline network that carries Canadian oil across the U.S. Midwest.

Michigan Gov. Gretchen Whitmer, a Democrat and Biden ally, has demanded closure of the 68-year-old line because of the potential for a catastrophic rupture along a 4-mile section in the Straits of Mackinac, which connects Lake Huron and Lake Michigan. The Biden administration has not taken a position but is under increasing pressure to do so.

Canada last month invoked a 1977 treaty guaranteeing the unimpeded transit of oil between the two nations.

Associated Press writer Colleen Long in Washington contributed to this report.