Eagle Pass, Texas — The number of migrants crossing the southern border without authorization increased in February after dropping in January, as the Biden administration prepares for a larger spike in migration this spring, two U.S. government officials told CBS News.

Border Patrol agents recorded approximately 140,000 migrant apprehensions between official ports of entry along the U.S.-Mexico border last month, up from 124,000 in January, when unlawful crossings plunged, the U.S. officials said, requesting anonymity to discuss internal and preliminary government data.

Another 50,000 migrants were processed at ports of entry, where the Biden administration is admitting those who use a government mobile app to secure an appointment to enter the U.S.

The number of migrant crossings in February is still far below the record levels of migration reported in December, when 302,000 migrants were processed by U.S. immigration authorities. But the increase in illegal entries from January indicates that migration is rebounding heading into the spring, when migrant arrivals have spiked in recent years. 

In fact, the number of migrant crossings has increased further in March, preliminary figures show. On some days this past week, U.S. border officials processed more than 7,000 migrants in 24 hours.

It’s unclear how long the upward trend in migrant crossings will last, since migration patterns are driven by complex factors, including actions by the Mexican government. After the record influx in crossings in December, the Biden administration convinced the Mexican government to ramp up efforts to stop and deport U.S.-bound migrants.

Illegal crossings have also shifted geographically in recent weeks. Most migrants have been crossing into remote parts of Arizona and California. In Texas, the state with the longest border with Mexico, migrant crossings are down significantly from last year. While Gov. Greg Abbott has said the shift stems from his actions, including the deployment of razor wire near the Rio Grande, U.S. officials said Mexican enforcement has been more pronounced near Texas.

The increase in migrant arrivals could further complicate an already tenuous political and operational situation for President Biden, whose administration has struggled to contain an unprecedented mass migration event. In the past two fiscal years, Border Patrol has recorded over 2 million apprehensions of migrants who entered the country illegally, the highest tallies in the agency’s history.

Polls indicate that immigration could be a top issue in the 2024 election, a potential rematch between Mr. Biden and former President Donald Trump, his Republican rival in 2020. It’s also one of Mr. Biden’s worst-polling issues.

To tackle the expected spike in border arrivals this spring, Mr. Biden is considering issuing an executive order to further restrict access to an outdated and over-saturated asylum system. One of the proposals would involve Mr. Biden invoking a sweeping authority used multiple times by Trump to disqualify migrants from asylum on the basis that their entry is “detrimental” to U.S. interests.

While he did not confirm Mr. Biden would use that legal authority, known as 212(f), Homeland Security Secretary Alejandro Mayorkas suggested that such a move would almost certainly be challenged in court by groups that advocate for migrants.

“Former President Trump invoked 212(f), a statutory provision, and that was enjoined by the courts,” Mayorkas said on “Face the Nation” Sunday. “And so when administrative actions are taken, they are often litigated, and they do not endure.”

“The American people deserve and expect enduring solutions and Congress needs to deliver on the American public’s expectations,” he added.

Earlier this year, a bipartisan group of Senators forged an immigration compromise with the White House that would have tightened asylum rules and given border officials the power to quickly deport migrants from the U.S. during spikes in crossings. Most Republicans in Congress rejected that deal almost immediately after it was released, saying it was not strict enough.