One of the most important diplomatic decisions by President Joe Biden at the gathering this week of North American leaders might have been his choice of airport.

Mr Biden arrived in Mexico City on Sunday evening via Mexico’s newest hub, the Felipe Angeles International Airport, a prized project by Mexican President Andres Manuel Lopez Obrador.

The hub was christened last year with much fanfare, though it is located more than an hour’s drive north of the city centre, has few flights and until recently lacked consistent drinking water.

Mr Biden and Mr Lopez Obrador, whose relationship is transactional at best and notably lacking the warmth and camaraderie the US leader has with other counterparts, shook hands and walked together down the red carpet on the tarmac, flanked by soldiers.

The two then took the long drive into the city centre together.

Along with Canadian Prime Minister Justin Trudeau, who arrives later on Monday, the trio will spend the next two days discussing climate change, manufacturing, trade, the economy and the potential global clout of a more collaborative North America.

“This gathering will deepen our coordination and advance our shared priorities for North America,” Mr Biden tweeted on Sunday after his arrival.

Migration will also be discussed, but ahead of the summit Mr Biden announced a major US-Mexico border policy shift, with Mexico’s blessing, that will result in the United States sending 30,000 migrants from four other countries per month back across the border.

The US will accept 30,000 people per month from the four nations – Cuba, Nicaragua, Haiti and Venezuela – for two years and offer the ability to work legally.

On Sunday, Mr Biden’s spent roughly four hours in El Paso, Texas, his first trip to the border as president and the longest he has spent along the US-Mexico line.

The day was highly controlled and seemed designed to showcase a smooth operation to process migrants entering legally, weed out smuggled contraband and humanely treat those who have entered illegally, creating a counter-narrative to Republicans’ claims of a crisis situation equivalent to an open border.

But it was likely do little to quell critics from both sides, including immigrant advocates who accuse the Democratic president of establishing cruel policies not unlike those of his hard-line Republican predecessor, Donald Trump.

Mr Biden encountered no migrants except when his motorcade drove alongside the border and about a dozen lined up on the Ciudad Juarez side in Mexico.

His visit did not include time at a Border Patrol station, where migrants who cross illegally are arrested and held before their release.

In El Paso, where Mr Biden did not visit, hundreds of migrants were gathered outside the Sacred Heart Catholic Church, where they have been sleeping outdoors and receiving three meals a day from faith groups and other humanitarian organisations.

When asked what he has learned by seeing the border first-hand and speaking with the officers who work along it, Mr Biden said: “They need a lot of resources. We’re going to get it for them.”

The number of migrants crossing the US-Mexico border has risen dramatically during Mr Biden’s first two years in office.

There were more than 2.38 million stops during the year that ended September 30, the first time the number topped two million. The administration has struggled to clamp down on crossings, reluctant to take measures that would resemble those of Mr Trump’s administration.

Mr Lopez Obrador will formally welcome Mr Biden at the Palacio Nacional on Monday, the first time since 2014 that Mexico has hosted a US president.

The two will meet before Mr Trudeau joins them for dinner. Mr Biden and Mr Trudeau will hold talks Tuesday, and then the three will gather for discussions.

For the U.S., the major talking points are migration, drug trafficking and building on Biden’s push on electric vehicles and manufacturing.

Mexico is focused on economic integration for North America, supporting the poor in the Americas and regional relationships that put all governments on equal footing.

Canada is looking to expand on green initiatives.

There are thorny issues to to consider. The leaders of Canada and Mexico have voiced concerns over Mr Biden’s “Buy American” plan. And while the American leader’s push toward electric vehicles is a boon to both nations because of the tax credits for North American batteries, there is concern the US allies will be left behind.

The US and Canada accuse Mr Lopez Obrador of trying to favour Mexico’s state-owned utility over power plants built by foreign and private investors, something that is forbidden under the three countries’ free trade pact.

Mr Biden’s relationship with Mr Trudeau is warmer, but he still hasn’t made it to Canada during his presidency, despite White House officials saying for months he planned to head north following a gathering in Los Angeles last autumn.