WASHINGTON — President Biden on Monday sought help from President Andrés Manuel López Obrador of Mexico in averting a new crisis at the border, hoping for diplomatic cooperation from one of the key supporters of the harsh tactics imposed by Mr. Biden’s predecessor to choke off immigration.
Mr. López Obrador won the admiration of President Donald J. Trump for cooperating with his hard-line immigration agenda, and the Mexican president praised Mr. Trump during a call with Mr. Biden, then the president-elect, in December.
Facing an uptick of illegal migrant crossings at some parts of the southwestern border, Mr. Biden is now hoping that Mr. López Obrador will become a partner in preventing another cycle of out-of-control migration from Central America, but that he will do so without resorting to the full range of policies Mr. Trump embraced. The Mexican president appeared open to collaboration, issuing a joint statement committing to address climate change, the pandemic and migration north.
Despite campaigning against Mr. Trump’s policies, Mr. Biden wants one of the same things from the Mexican president that his predecessor did: help in keeping Central American migrants from immediately surging north toward the United States through Mexico.
While Mr. Biden has presented himself as breaking sharply with Trump administration immigration policies, he has abandoned only some.
The president has recently begun welcoming back to the United States a limited number of asylum seekers who were exposed to violence and kidnappings in dangerous areas of Mexico under a Trump-era program. But the Biden administration has kept in place a separate Trump policy that empowers agents to rapidly expel new arrivals at the border to Mexican authorities as Mr. Biden hopes to avoid a crisis that challenged his predecessors.
Both policies were accepted by Mr. López Obrador with little resistance when they were first imposed by Mr. Trump.
Mr. López Obrador recently called for a new guest worker program for Mexicans and Central Americans in the United States, although Mr. Biden’s press secretary said on Monday the move would require legislation from Congress.
But while Mr. Trump initially threatened Mexico with tariffs and a shutdown of the border to win cooperation with his immigration agenda, Mr. Biden heaped praise on Mr. López Obrador on Monday. Mr. Biden has also signaled that he is eager to open the U.S.-Mexico border to full trade when the pandemic allows it to happen.
“The United States and Mexico are stronger when we stand together,” Mr. Biden said at the beginning of a virtual meeting with the Mexican president, while acknowledging that the countries have not been “perfect” neighbors. He said that during the Obama administration, “we looked at Mexico as an equal — you are equal.”
The conversation came after a tumultuous start between the two leaders. Mr. López Obrador, one of the last leaders to congratulate Mr. Biden on his election victory, had come to see the Biden administration as potentially more meddlesome than Mr. Trump’s, which mostly refrained from pressuring the Mexican president on domestic matters.
Mr. López Obrador also recently adopted a measure to restrict cooperation with American narcotics agents in a sharp rebuke after the United States arrested a former Mexican official on drug trafficking charges.
“What you do in Mexico and how you succeed affects the rest of the hemisphere,” Mr. Biden told him.
Mr. López Obrador later told Mr. Biden that “it is important that we base our good relationships on constant dialogue, periodic dialogue.”
Before the meeting, Alejandro N. Mayorkas, the homeland security secretary, denounced what he called the “depths of cruelty” of the Trump administration’s immigration philosophy, telling reporters that the separation of families at the border was “the most powerful and heartbreaking example” of Mr. Trump’s assault on the immigration system.
But even as Mr. Biden seeks to unwind those policies, Mr. Mayorkas acknowledged that the United States continued to rely, for now, on a measure at the heart of Mr. Trump’s approach: a public health rule that requires border agents to quickly deport border crossers to Mexico without a chance to request asylum.
“They need to wait,” Mr. Mayorkas said of potential asylum seekers. “It takes time to rebuild the system from scratch.”
Mr. Biden has made immigration one of his top legislative and diplomatic priorities, moving quickly to raise Trump-era limits on refugees who can be allowed into the United States and calling on Congress to pass a far-reaching bill that would give a path to citizenship to 11 million undocumented immigrants already living in the country.
The Biden administration has also formed a task force to unite parents separated from their children under Mr. Trump’s family separations policy. Mr. Mayorkas said on Monday that Michelle Brané, the former director of migrant rights and justice at the Women’s Refugee Commission, would lead the effort to unite the families, who could be provided the option to remain in the United States permanently. Mr. Mayorkas stopped short of promising the parents citizenship.
Republicans have already signaled that they intend to seize on Mr. Biden’s reversals of his predecessor’s immigration policies as a cornerstone in their efforts to take back Congress in 2022 and recapture the White House two years later.
In an echo of his successful 2016 campaign, Mr. Trump has already offered a road map for Republican candidates in 2022 by once again exaggerating the situation at the border and falsely stating that Mr. Biden’s approach is “to cancel border security.”
Mr. Mayorkas rejected the assertion that the situation at the border had evolved into a crisis, even as Customs and Border Protection reassigned agents from coastal and northern borders to the Rio Grande Valley “due to fluctuations along the southwest border,” according to an agency statement.
“There is a challenge at the border that we are managing,” Mr. Mayorkas said.
While Mr. Biden is unwinding the Migrant Protection Protocols program that forced migrants to wait in Mexico for an adjudication in their asylum cases, he has kept another Trump-era rule in place that empowers border agents to swiftly expel migrants and turn them over to Mexican authorities.
Both the Biden and Trump administrations have said the policy is necessary to prevent the spread of the coronavirus in border communities, even as advocates for immigrants say it diminishes the due process rights of asylum seekers.
Border agents encountered a migrant at the border about 78,000 times in January, the highest number for that month in at least a decade, according to data from Customs and Border Protection. More than 80 percent of those arrests resulted in the swift expulsion of the migrant under the emergency rule, rather than the processing of a migrant in a detention facility.
Mr. Biden is not using the rule to expel unaccompanied migrant children, a practice that under Mr. Trump caused families to scramble to find Central American children and violated a diplomatic agreement with Mexico. Instead, under the Biden administration, most of the unaccompanied children, arriving from Central America by the hundreds per day, are being placed in quarantine and shuttled to shelters in the United States until they are matched with a relative sponsor.
With border detention facilities already at restricted capacity because of the pandemic, the Biden administration also opened a temporary shelter in Texas to house migrant teenagers. The use of temporary shelters faced widespread criticism during the Trump administration.
The new administration is hoping the temporary facilities are enough until it builds up infrastructure at the border. In the meantime, Mr. Biden continues to rely on Mr. Trump’s pandemic emergency rule to turn away new arrivals at the border.
Despite the emergency rule, border agents have for weeks released a limited number of families into communities in South Texas because of a change in Mexican law that has been the subject of internal discussions between Mexican and American government officials in recent weeks, according to a senior administration official.
Biden administration officials have said the recent change in Mexican law that prohibits the detention of small children in the state of Tamaulipas has forced border agents to release dozens of families per day into border communities in the United States. The Customs and Border Protection agency does not test each migrant for the coronavirus but relies on local officials to provide testing to the families after they are released, causing widespread concern in border communities, said Representative Henry Cuellar, Democrat of Texas.
At the same time, pandemic restrictions remain in place on nonessential travelers who have long stimulated the local economy along the border, he said.
The increase in migration, Mr. Cuellar said, has made the relationship with Mexico even more crucial. “The whole key is, how are they going to work with us?” he said.