With national attention focused on the chaos at the southern border, President Biden has been steadily rebuilding a legal pathway for immigration that was gutted during the Trump administration.

The United States has allowed more than 40,000 refugees into the country in the first five months of the fiscal year after they passed a rigorous, often yearslong, screening process that includes security and medical vetting and interviews with American officers overseas.

The figure represents a significant expansion of the refugee program, which is at the heart of U.S. laws that provide desperate people from around the world with a legal way to find safe haven in the United States.

The United States has not granted refugee status to so many people in such a short period of time in more than seven years. The Biden administration is now on target to allow in 125,000 refugees this year, the most in three decades, said Angelo Fernández Hernández, a White House spokesman.

By comparison, roughly 64,000 refugees were admitted during the last three years of the Trump administration.

“The Biden administration has been talking a big talk about resettling more refugees since Biden took office,” said Julia Gelatt, an associate director at the Migration Policy Institute, a nonpartisan research group in Washington. “Finally we are seeing the payoff in higher numbers.”

But as the presidential campaign heats up, immigration advocates fear that the gains will be wiped out if former President Donald J. Trump is elected. The former president has vowed to suspend the program if he takes office again, just as he did in 2017 for 120 days.

Mr. Trump has characterized the program as a security threat, even though refugees go through extensive background checks and screening. He reassigned officers, shuttered overseas posts and slashed the number of refugees allowed into the country every year.

The result, when Mr. Biden took office, was a system devoid of resources.

“The refugee program hangs in the balance with this election,” said Barbara L. Strack, the former lead refugee official at U.S. Citizenship and Immigration Services.

‘Like my birthday’

The refugee program gets far less attention than the country’s asylum system, which is buckling under the weight of millions of new arrivals at the southern border.

The paths to claiming asylum and refugee status are separate. Potential refugees apply for the program overseas and wait there during the screening process. Those seeking asylum ask for it when they step on American soil, and their claims must then wend their way through a backlogged immigration court system.

Mr. Biden has taken a tougher line on asylum in recent months as he faces growing pressure to bring some sort of order to the southern frontier.

The refugee program historically has had strong bipartisan support, in part because it was seen as the “right way” to come to the United States.

Senator John Cornyn, Republican of Texas, said in a congressional hearing last year that the process for the refugee program was “sound.” He said he did not view the program as a “substantial” safety risk and said the program’s robust checks stood in “contrast to the chaos we see at the southern border.”

Still, some of that bipartisan support has eroded as the number of people crossing the southern border has reached record levels. Mr. Trump has made his anti-immigrant platform a hallmark of his political identity as he calls for sealing off the country from immigrants — both legal and illegal.

But for people like Machar Malith Geu, who lived in a refugee camp in Kenya for most of his life, the opportunity to come to America felt like his only hope for the future.

It took six years, but his application to be resettled in the United States was approved and he arrived here in February. His new home is in Wichita, Kan.

“Being accepted to come to the United States of America, it was like my birthday again, because I knew I will leave the life of a refugee behind me,” said Mr. Geu, whose family fled what is now South Sudan in the 1990s.

Mr. Geu, 33, said he did not consider making his way to the U.S.-Mexico border and crossing illegally. In recent years, the southern border has seen an uptick in migration from African countries, including Mauritania, Senegal and Angola.

“I never dared to come illegally to America or any other place,” he said. All he was hoping for, he said, was “to stay alive.”

Now, he has applied for a work permit and wants to become a security guard before bringing his wife and three daughters to the United States. While he’s waiting, he has found solace playing pickup basketball with refugees from Sudan and Congo.

After refugees are approved for resettlement, the U.S. government provides funding for cultural orientation classes and connects them to local groups that help them get on their feet with job training, food and housing.

Refugees must apply for a green card within a year of arrival in the United States. Later, they can get American citizenship.

Rebuilding

The Biden administration inherited a program that had been stripped to the bone during the Trump years.

Mr. Trump repeatedly warned that refugees were a threat. He said during a 2020 rally in Minnesota that refugees were coming from “the most dangerous places in the world, including Yemen, Syria and your favorite country, Somalia, right?”

At one point, Mr. Trump allowed states and cities to refuse to accept refugees, a measure that was later blocked in federal court.

The International Rescue Committee said, contrary to Mr. Trump’s assertions, that “the hardest way to come to the U.S. is as a refugee.”

“Refugees are vetted more intensively than any other group seeking to enter the U.S.,” the group said in a statement. “All those seeking to come here must first be registered by the United Nations refugee agency, which identifies the families most in need. The U.S. then hand-selects every person who is admitted.”

By the end of his administration, Mr. Trump had cut the “refugee cap,” or the maximum number of refugees who could be allowed in a single fiscal year, to 18,000 in 2020 and a proposed record low of 15,000 in 2021.

Because funding for local programs is tied to that figure, money dried up fast.

Many organizations that help resettle refugees were forced to close their doors. The officer corps that handled refugee interviews dropped from around 170 to 107 by the end of the Trump administration, according to government data.

“I was feeling pretty demoralized,” Sandra Vines, senior director of refugee resettlement at the International Rescue Committee, said of the Trump years. “I felt like every day I would come into the office and there was another administrative attack on the program. We called it death by a thousand paper cuts.”

The pandemic also contributed to low refugee admissions in the early years of the Biden administration. In the 2021 fiscal year, which included part of the Trump administration, the United States allowed in just over 11,000 refugees. The next year, it allowed more than 25,000.

The Biden administration has worked to rebuild the infrastructure for the program. About 150 refugee resettlement offices have opened around the country, and the number of refugee officers conducting interviews has also increased.

The signs of a more robust refugee program began to show last year when more than 60,000 refugees were admitted into the country. It was a far cry from the limit of 125,000 set by Mr. Biden, but it proved that the program was handling more cases.

Beyond the added resources, the Biden administration has streamlined processing and opened up so-called Safe Mobility Offices in Colombia, Guatemala, Ecuador and Costa Rica to help take in applications from migrants and expand refugee processing from the region.

“A lot of people wished to see the increased admissions sooner, but I think understanding what it takes to make a program successful — those hopes were not realistic,” said Ms. Strack, the former refugee official.

“We’re just seeing the fruits of all of the labor now.”