WASHINGTON — In his final debate with Donald J. Trump on Oct. 22, 2020, Joseph R. Biden Jr., then a candidate, excoriated his rival for radically undermining America’s decades-long tradition of welcoming people who seek asylum at the country’s borders.

“This is the first president in the history of the United States of America that anybody seeking asylum has to do it in another country,” Mr. Biden said, referring to one of hundreds of Trump-era immigration policies aimed at shutting down the border.

Yet on Thursday, Mr. Biden’s administration is expected to impose a very similar restriction on asylum seekers by quickly rejecting claims for most people who cross the border but do not seek refuge in Mexico first. Like Mr. Trump’s policy, the new approach is likely to lead to many migrants being deported in a swift process that critics say deprives them of due process.

After nearly two and a half years in office, Mr. Biden has struggled to settle on an approach to immigration that satisfies his critics on the right or the left. In some cases, he has embraced his predecessor’s use of aggressive measures aimed at keeping a surge of migrants at bay along the southern border.

Still, Republicans have attacked him for policies that make it easier to immigrate to the United States even as human rights groups and migrant activists assail his embrace of tougher measures designed to keep people out.

The announcement of the tough new approach to asylum — which immigration activists have vowed to challenge in court — comes as Mr. Biden’s administration prepares to end another Trump-era policy known as Title 42, which has effectively kept the border closed to asylum seekers since the beginning of the coronavirus pandemic three years ago.

The president has taken some steps aimed at welcoming migrants and ending what he once called the “moral and national shame” of Mr. Trump’s immigration policies. He has vowed never to separate families at the border, as Mr. Trump did in the summer of 2018. And his administration has moved to let in more migrants from places like Ukraine, Afghanistan and several Central American countries.

On the first day of his administration, Mr. Biden introduced legislation that would provide a path to citizenship for 11 million undocumented immigrants, protect so-called Dreamers, and expand visas for workers, families and visitors. Republicans uniformly opposed the proposal, which has gone nowhere. Conservative judges, egged on by Republican governors and lawmakers, have also blocked other immigration efforts by the administration.

But surges of migrants displaced by political and economic turmoil — and the Republican Party’s use of those images to foster a narrative that the border is out of control — have shaped Mr. Biden’s immigration policies in ways that few of his allies imagined when he was running for president.

Heidi Altman, the policy director at the liberal National Immigrant Justice Center, said the Biden administration has made some “important steps” toward more humane policies for migrants. But she criticized what she called a “web of policies” similar to Mr. Trump’s.

“These are policies designed to make it difficult or impossible for people in need of safety to get it, and even punish them for trying,” she said.

The administration does not shy away from its use of tough rules, arguing that the best way to discourage migrants from making the dangerous trek to the border is to ensure there are consequences for crossing illegally. In a memo distributed to reporters last week, the White House proudly summarized its approach to the sensitive topic.

“The Biden-Harris Administration’s plan is rooted in enforcement,” the memo said, adding that the effort also entails “deterrence” and “diplomacy” with other countries.

Immigration officials are quick to point out that they have paired tougher enforcement with new opportunities for migrants, including programs that allow migrants from Venezuela, Cuba, Nicaragua and Haiti to apply for a special two-year entry program rather than take their chances by crossing the border.

After being blocked by the courts, the administration eventually ended a Trump administration policy called “Remain in Mexico,” which forced asylum seekers to wait in dangerous conditions in Mexico while their cases were processed in the United States.

White House officials flatly reject the notion that Mr. Biden’s immigration agenda is similar to Mr. Trump’s. They noted that on Monday, Mr. Biden threatened to veto House Republican legislation that would restore some of the former president’s harshest ideas, including construction of a border wall.

“Donald Trump demanded more money for an ineffective border wall that couldn’t even withstand heavy winds, let alone sophisticated criminal smuggling networks,” said Abdullah Hasan, a White House spokesman. “President Biden is urging Congress to provide for more asylum officers, immigration judges, and border security technology.”

Still, advocates for migrants and some Democrats say the president and his team have moved far too slowly to dismantle Mr. Trump’s harsh policies. They point to, among other things, a decision by the former president to require migrants who were allowed to seek asylum to be interviewed immediately after being captured, while still in Border Patrol custody.

That decision prevented many migrants from having the time to prepare their case and get a lawyer, activists said at the time. The number of migrants approved for asylum plummeted — exactly the result that Trump administration officials wanted.

Now, Mr. Biden’s administration is taking a similar approach to speeding up deportation of migrants at the border. People who seek asylum are now interviewed by phone within hours of being moved into Border Patrol custody. If they are denied asylum, many are deported back to Mexico or to their home countries within hours, according to immigration lawyers.

Administration officials note that they have added many phone booths to Border Patrol facilities and now provide lists of pro bono attorneys to migrants. Unlike under the policy under Mr. Trump, asylum interviews are not conducted by Border Patrol officers.

One of the most draconian policies adopted by Mr. Trump was the use of the public health rule known as Title 42, which effectively closed the border to most asylum seekers by arguing that the action was needed to prevent the spread of Covid-19 at the start of the pandemic.

When Mr. Trump used Title 42 powers at the start of the pandemic in 2020, it was part of a broader effort by Stephen Miller, the architect of the administration’s immigration agenda, to achieve his real goal: the effective end of America’s seven-decade asylum system.

Critics assailed the move at the time. Amnesty International accused Mr. Trump’s administration of “weaponizing Covid-19 to achieve the policy objective it’s sought from Day 1: shutting the border.” Democrats vowed to reverse the policy immediately.

But when he took office a year later, Mr. Biden did no such thing. He argued that it was up to the Centers for Disease Control and Prevention, which continued to extend the public health emergency that allowed Title 42 to be invoked. After the C.D.C. said Title 42 was no longer needed in April 2022, the administration moved to end it but was blocked by conservative judges.

The administration then expanded the use of Title 42 in October before being allowed by the courts to end it for good this week. But that is too little, too late to convince advocates that the Biden administration is in the right place.

“People seeking safety now need access to asylum, and U.S. laws afford them that right,” Ms. Altman said. “The administration is eviscerating that access, in the same vein as the Trump administration.”