EL PASO — Vice President Harris on Friday made her first visit to the U.S. southern border since her inauguration, facing sharp criticism from Republicans who claim White House immigration policies are too lax as well as critiques from liberal advocates who argue President Biden is continuing the harsh policies of his predecessor.

Harris’s 4½ hours in this border city are likely to do little to blunt the complaints that have followed her as she tries to manage the assignment Biden gave her in March to address the root causes of illegal immigration from south of the border.

Harris has sought to emphasize that her designated role is to grapple with the forces that push migrants to head to the United States, rather than to manage problems at the border itself — an argument that has done little to shield her from political attacks from the left and the right.

Republicans began assailing Harris’s trip even before Air Force Two touched down, calling it a “layover” in El Paso and saying the vice president was avoiding parts of the border where the greatest migrant influxes have happened under the Biden-Harris administration. On the other flank, Amnesty International accused Biden of “falling back on dangerous practices pushed by the Trump administration” despite campaigning on the promise of a more humane system.

After touring the port of entry and border operation at El Paso, Harris stressed that she was focusing on resolving problems thousands of miles away in Central America.

“My trip to Guatemala and Mexico was about addressing the root causes,” Harris said at the end of her El Paso trip, referring to a recent visit to those countries. “The stories that I heard and the interactions that we had today reinforced the nature of those root causes: a lack of economic opportunity, very often violence, corruption and food insecurity, and the basic needs not being met, including fear of cartels and gang violence.”

Many administration allies worry that her visit to the border plays into the hands of Republicans who have sought to tie Harris to a chaotic surge in irregular migration during Biden’s first months in office. Some GOP leaders and conservative pundits have dubbed her Biden’s “Border Czar” in hopes of making her the face of an issue that for decades has proved intractable for presidents from both parties.

If the argument sticks, it could damage Democrats in the midterm elections despite their success in passing a $1.9 trillion pandemic relief bill and recently making progress on an infrastructure measure. The label also could stain the reputation of Harris, who is widely considered a future presidential aspirant.

Harris’s visit also offered a new foothold for arguments from immigrant advocates who contend that Biden’s approach to immigration enforcement contains vestiges of President Donald Trump’s hard-edged border policies.

The administration faces growing pressure to rescind the use of a public health order instituted under Trump that lets immigration authorities turn away border crossers and asylum seekers because they may be carrying the novel coronavirus. Critics say the order, known as Title 42, is inhumane and sometimes returns vulnerable migrants to the dangerous situations they fled. The critics also say the order is increasingly unnecessary as more Americans are vaccinated and the United States makes strides against the virus.

Linda Rivas, the director of Las Americas Immigrant Advocacy Center, who was among community leaders who met with Harris on Friday, said in a statement that the White House “must improve the asylum process and end the cruel border policies that ripped families apart, like the ‘Remain in Mexico’ and Title 42 policies.” She added that the administration must “build an asylum system that welcomes people with dignity and respect.”

The “Remain in Mexico” program established under Trump sends migrants who cross the border from Mexico back into that country to await U.S. asylum hearings, part of an effort to limit access to the United States and deter people from attempting the journey north.

Trump, who is to visit the border with Texas Gov. Greg Abbott (R) on Wednesday, pounced shortly after Harris’s trip was announced this week, saying that his coming trip had forced Harris’s hand.

“After months of ignoring the crisis at the Southern Border, it is great that we got Kamala D. Harris to finally go and see the tremendous destruction and death that they’ve created — a direct result of Biden ending my very tough but fair Border policies,” Trump said in a statement.

Harris and her advisers said the border trip was part of a continuing effort to understand the journey of migrants from start to finish and that politics did not play a role in her decision to visit.

But they have also stressed that El Paso is the site of the “launch” of the Trump administration’s policy of separating children from their parents at the border, which both Biden and Harris blasted on the 2020 campaign trail as inhumane. During her meeting with faith and community leaders Friday, Harris spoke of efforts to mend a “broken asylum system” and said Homeland Security Secretary Alejandro Mayorkas was expediting a process to reunite families separated during Trump’s tenure.

“It is here in El Paso that the previous administration’s child separation policy was unveiled,” Harris said. “And so we’ve seen the disastrous effects of that right here in this region. It is here in El Paso that the Return to Mexico policy from the previous administration was implemented. We have seen the disaster that resulted from that.”

Later, she added that El Paso is where unaccompanied minors “are without their families — young children — they’re being processed through the system.”

In addition to meeting some of those unaccompanied minors, the vice president and Mayorkas toured the city’s Central Processing Center, where Harris heard about advances aimed at efficiently processing migrants and combating transnational crime. She also visited the port of entry in El Paso, touring an area where border agents screen asylum applicants and search vehicles.

In March, President Biden tasked Harris with tackling the root causes of migration from the Northern Triangle countries: Guatemala, El Salvador and Guatemala.

During her visit to Guatemala and Mexico this month, Harris met with the presidents of both countries and unveiled a raft of aid that the Biden administration hopes will give potential migrants enough faith in the future of their home countries to deter them from making the 2,000-mile trip to the U.S. border. Harris also sent an explicit message to those considering the journey: “Do not come.”

But that two-day journey provided a stark contrast to Friday’s brief trip to the border. Administration officials announced the trip to Guatemala and Mexico weeks in advance and made accommodations for a large contingent of international journalists. Harris took questions from reporters on both days and announced the aid that the United States was extending to Central American countries.

By comparison, the White House announced that Harris would visit El Paso just two days before the trip, saying the stop was wedged between a busy week in Washington and a planned weekend at the vice president’s California home. She traveled with a few journalists who provided pool reports.

At the end of the day, some were calling the trip inadequate. Among them was Rep. Henry Cuellar (D-Tex.), who in recent weeks had written a letter urging Harris to visit the border.

“I’m glad that she checked the box and went to the border,” Cuellar told CNN. “But the epicenter is down in the Rio Grande Valley. If you really want to get a sense of what’s going on, you need to go down to Donna, Texas.”

Nick Miroff in Washington contributed to this report.