▶ Watch Video: Border cities brace for expected migration increase once Title 42 expires

Anita Dunn, one of President Biden’s highest-ranking White House aides, said on Thursday that congressional critics of the administration’s strategy to deal with the high levels of unauthorized arrivals along the U.S.-Mexico border should focus on reforming the outdated U.S. immigration system.

In an interview with CBS News political correspondent Cailtin Huey-Burns on “America Decides,” Dunn called on lawmakers to “update our immigration laws to reflect the realities of 2023,” noting that the last time Congress passed major immigration legislation was decades ago, in the 1990s.

“It’s interesting to listen to members of Congress criticize this administration given the fact that it has been 37 years since Congress last passed immigration laws in this country. And they all know that,” said Dunn, who serves as Mr. Biden’s senior adviser. “The basic problem here is those laws need to be updated.”

Dunn noted the administration was acting unilaterally to “manage the border problems,” citing the deployment of 1,500 troops to the U.S.-Mexico border to provide operational support to Border Patrol agents, the establishment of migrant processing centers in Colombia and Guatemala and efforts to increase the number of beds at migrant detention centers.

Throughout his tenure, Mr. Biden has faced strong criticism from Republicans, and some Democrats, over how his administration has handled a record number of migrant apprehensions along the southern border. But the criticism has intensified recently as border officials prepare to wind down a pandemic-era emergency rule, known as Title 42, that has allowed them to turn back migrants without hearing their asylum claims.

The termination of Title 42, set to be triggered by the expiration of the COVID-19 public health emergency on May 11, is expected to fuel a sharp increase in illegal crossings along the southern border. While migrant arrivals have already increased in recent days, Border Patrol is bracing for more than 10,000 migrants to enter U.S. custody each day starting next week.

The Biden administration has said that recently announced measures, including an increase in deportation flights, a restriction on asylum eligibility and expanded legal migration programs, will help the U.S. manage migrant arrivals post-Title 42 and discourage migrants from crossing into the U.S. without authorization.

But Republicans, centrist Democrats and local officials have warned that the spike in migration threatens to overwhelm shelters, volunteers and communities along the southern border. Democratic mayors in New York and other major cities receiving migrants have also said they’re in need of more federal support.

On Thursday, Republican Sen. Thom Tillis of North Carolina said he planned to team up with independent Arizona Sen. Kyrsten Sinema to introduce a bill that, if enacted, would allow border agents to continue expelling migrants without the public health order underpinning the Title 42 expulsions. Without sufficient Democratic support, however, the measure would face steep odds in the Democratic-led Senate.

Asked if the administration would support such a bill, Dunn said the White House had not yet seen the proposal. 

But she noted that “the bipartisan nature of this perhaps would be helpful in bringing a broader coalition together in Congress to finally fix this.”