At 5,525 miles, it is the longest border between any two countries. And that border — separating the United States and Canada — seems set to become a flashpoint between the close allies as President-elect Donald Trump prepares to take power.
Canadian authorities fear that Trump’s promised mass deportations will push migrants north, while allies of the incoming president headed for key roles in his administration have raised alarms over a recent spike in migrants crossing from Canada to the United States without legal permission.
Canadian officials are drawing up plans to add patrols, buy vehicles, and set up emergency reception facilities at the border between New York state and the province of Quebec to prepare for what they expect to be a surge in migrants because of Trump’s hard line on deportations.
The northern border is also a focus of people named to top positions in the Trump administration, including his new border czar, Tom Homan. He has described the frontier as a major security vulnerability because of what he described as insufficient checks on people entering the United States.
Concerns over the northern border highlight a key shift in Canada’s view of migration between the first and second Trump administrations. During the first, Prime Minister Justin Trudeau of Canada made it clear that asylum-seekers were welcome in Canada just as Trump was tightening asylum rules and introducing policies including family separation at the US southern border.
“To those fleeing persecution, terror & war, Canadians will welcome you, regardless of your faith. Diversity is our strength #WelcomeToCanada,” Trudeau posted on social media at the time.
Today, the mood in Canada is very different. Many Canadians believe the arrival of more legal migrants since the end of the pandemic has strained resources such as housing, and have blamed Trudeau’s government, which is now taking steps to significantly limit legal immigration.
Trump, for his part, has become more aggressive on immigration, asserting he intends to crack down and deport millions of migrants illegally in the country. His allies have criticized Canada for not controlling the northern border, where arrivals of migrants into the United States without legal permission hit a record high this summer.
Canadian officials say they are fortifying the border and will deport migrants who attempt to enter Canada to escape Trump’s crackdown. The Royal Canadian Mounted Police, which guards the border, is preparing to beef up its numbers if there is a surge in three key ways — more staff, more vehicles, and more detention and processing facilities — said a spokesperson for the agency, Sergeant Charles Poirier.
Officials are anticipating an increase in migrant crossings even before Trump’s inauguration in January. “We knew that, if Mr. Trump came into power, the status quo at the border would change,” Poirier said.
The mounted police have identified enforcement agencies that could be tapped to divert extra staff to the border. The agency would also seek to add more patrol vehicles and use land along the border to set up trailers or other types of temporary detention and processing facilities.
Canada’s national security agencies “have been preparing for a number of months to be ready to respond and adapt to any situation that might arise,” said Gabriel Brunet, a spokesperson for Dominic LeBlanc, Canada’s minister of public safety.
Canadian authorities also intend to wield a key agreement between the two countries to send back people crossing into Canada to seek asylum. The agreement designates Canada and the United States as “safe third countries” in which to make asylum claims, so when asylum-seekers travel from one country to the other, they can be sent back, with few exceptions.
“The reason that exists is that the United States is deemed to be a safe country for people to make their initial asylum claim,” Marc Miller, Canada’s immigration minister, told reporters recently. “So too with Canada — it’s a two-way street.
“We expect that agreement to continue to be fully enforced,’’ he said.
Provincial leaders in Quebec are also anxious about the need to harden the border with New York and have already raised complaints about the growing number of legal immigrants and refugees who have settled there in recent years.
“The problem isn’t immigrants, it’s the number,’’ François Legault, the premier of Quebec, said at a recent news conference. “We already have too many. So we shouldn’t add to the problem.”
The border has come under scrutiny in both countries over the past year because of a surge in arrivals from Canada to the United States.
Official data from the US Borders and Customs Protection agency show that from October 2023 to September 2024, more than 19,300 migrants illegally in the country were apprehended by US authorities at the border between Quebec and Vermont, New York state, and New Hampshire, a 300 percent jump from the 6,925 apprehended during the same period the previous year.
More than 12,000 of the 19,300 people detained were Indian nationals, underscoring a booming migrant smuggling route from India to the United States via Canada.
Some of this smuggling is encouraged online. Indian nationals in Canada say videos circulate on TikTok from “travel agencies’’ marketing smooth transport to the United States. These videos are also flooding social media in India, promising a route to the United States in exchange for thousands of dollars.
With minimal resources at the northern border, few people were being sent back to Canada earlier this year. Instead, migrants were being released from custody with notices to appear in US immigration courts, which face an enormous backlog.
But starting this summer, US officials deployed more federal officials to the northern border to help process people and transferred more people into detention.
They also made a key change to make the process to return migrants to Canada easier: Starting in August, migrants who had been detained had only four hours to find a lawyer and collect evidence for their case, according to an internal email sent to asylum officers working for the Department of Homeland Security and reviewed by The New York Times. Before, migrants were given at least a day to do both.
Since then, the numbers of crossings have dropped dramatically — from roughly 3,600 crossings in June to around 1,800 in September — while the number of migrants returned to Canada has increased.
This article originally appeared in The New York Times.