Originally Published: 15 MAY 23 01:54 ET

Updated: 15 MAY 23 14:27 ET

By Nouran Salahieh, Polo Sandoval, Rosa Flores, Andrea Cambron and Priscilla Alvarez, CNN

(CNN) -- Despite warnings about a potential surge in migrants that sent thousands of federal personnel to the southern US border, officials said the days after the expiration of a Covid-related border restriction policy known as Title 42 saw fewer migrants arriving at the border than initially expected.

Ahead of the policy's expiration, long lines formed at checkpoints and makeshift encampments proliferated in border communities.

But US authorities saw a 50% drop in the number of migrant encounters along the border over the previous two days compared to earlier in the week -- before Title 42 ended -- Homeland Security Secretary Alejandro Mayorkas told CNN's Dana Bash on Sunday. US and Mexican officials say the Biden administration's warnings to asylum seekers and displays of immigration enforcement have deterred more migrants from crossing the border illegally.

The situation at the border is "very fluid," a senior Homeland Security official told reporters Monday.

"The decreased level of encounters at the border, we hope reflect both an appreciation of the new consequences that are in place for unlawful entry at the border as well as the enforcement actions being taken by our foreign partners," Homeland Security Assistant Secretary for Border and Immigration Policy Blas Nuñez-Neto said during a Monday briefing, noting that it is too early to draw firm conclusions.

The US has deported thousands of people, including more than 2,400 people to Mexico over the last three days, Nuñez-Neto said. The US and Mexico recently struck an agreement to deport certain non-Mexican nationals to Mexico. Nunez-Neto cautioned that people smugglers will try to take advantage of shifts in policy.

There were about 6,300 border encounters on Friday, and 4,200 on Saturday, Mayorkas said, adding that the number stood at around 10,000 before the Title 42 policy ended.

Mayorkas, however, warned it's too early to say whether the surge in migrants at the border has peaked.

Many who leave their homes and head to the US make long and dangerous treks in hopes of finding better, safer lives. Some may be fleeing violence, experts say, while others may be immigrating for economic opportunities or to reunite with family.

At a shelter in El Paso, Texas, where families marked Mother's Day waiting in limbo, migrant mothers told CNN it was their maternal instinct to provide for their children that drove them to make the perilous journeys to the US.

"A parent will do anything to see their children safe," said Conny Barahona, a migrant from Honduras who was at the shelter with her 9-year-old.

She waited there for her two other daughters -- an 18-year-old and a 20-year-old -- before traveling to their next destination.

"We left Honduras together and that's how we must remain," she said.

Title 42, a controversial Trump-era policy from the start of the Covid-19 pandemic, allowed authorities to swiftly turn away migrants encountered at the US-Mexico border. The policy ended last week, along with the national coronavirus public health emergency.

In the lead-up to the policy's expiration, authorities warned of a potential migrant surge that could worsen conditions at already strained border facilities. In anticipation, resources were surged to the border to support local authorities.

US cities prepare

Even as US cities are seeing lower numbers of migrants than expected, they are preparing spaces and resources for a potential surge.

Non-profit organizations in the Rio Grande Valley of south Texas say they've seen a steep drop in migrants since Title 42 ended.

Still, the border town of Laredo, Texas, is on "high alert," the city's mayor, Victor Treviño, told CNN's Jim Acosta on Sunday, noting that its hospitals were near capacity before Title 42 expired.

In El Paso -- which has seen hundreds of migrants sleeping on sidewalks after a recent spike in arrivals -- Mayor Oscar Leeser said the city has so far seen a "smooth transition" out of Title 42 but is still preparing for what the future may hold.

Brownsville Independent School District in Texas announced Monday that it expects to utilize school campuses currently not in use to process and provide services to migrants.

Mayors of other US cities, worried an influx of migrants will strain resources, are looking to the federal government for assistance. Denver Mayor Michael Hancock told CNN on Monday that he, along with mayors from the District of Columbia, New York City and Chicago, have reached out to the White House to request a meeting with Biden to discuss the situation.

New York City's Roosevelt Hotel in Midtown Manhattan, which has been closed for nearly three years, will reopen as an arrival and resource center for incoming migrants. The hotel will open 175 rooms for children and families this week, with plans to scale up capacity to around 850 rooms, a statement from the mayor's office said.

The city says it currently has about 35,000 migrants in its care.

"Without federal or state assistance, we will be unable to continue treating new arrivals and those already here with the dignity and care that they deserve," Mayor Eric Adams said in a statement Saturday.

In Washington, DC, a busload of migrants arrived at the Naval Observatory on Sunday evening. The bus originated from Texas, according to a source familiar with the situation who is unauthorized to speak on the record.

Texas Gov. Greg Abbott has bused thousands of migrants to Democratic-led cities since last year as an affront to President Biden's border policies. He recently ramped up his efforts, with at least two buses arriving at the Naval Observatory last week.

Biden administration's tough talk

The Biden administration has warned of grave consequences for migrants circumventing the lawful pathways for asylum. Community leaders and officials in Mexico say that kind of tough talk, along with the administration's display of immigration enforcement, is deterring more migrants from crossing the border illegally.

In the northern Mexican city of Tijuana, Enrique Lucero, the city's director of migrant affairs, attributes the drop in illegal crossings to the Biden administration's messaging and to the Mexican government's deployment of the national guard to the border. "We've seen images of (deportation) planes that have arrived in Guatemala, El Salvador and Honduras," Lucero said. "The five-year bar (on reentry to the US) has opened migrants' eyes."

The five-year ban on reentry Lucero referenced is one of the possible legal consequences migrants face under Title 8 immigration processing if they are deported from the US. Title 8 is the decades-old protocol that US immigration officials reverted to after Title 42 ended last week.

In the northern Mexican city of Reynosa, Pastor Hector Silva runs two prominent migrant shelters, and says that word is also spreading online -- through various chat groups -- about the consequences of crossing illegally into the US. "Don't cross because if you cross, you'll get deported," Silva says some of the online messages say.

"They (migrants) thought that with the end of Title 42 the border would be open; but they've realized that's not the case," Lucero said.

Lucero said in Tijuana illegal crossings have been facilitated by smugglers who charge migrants about $500 dollars; but the presence of the Mexican National Guard on Mexico's northern border -- which started last Wednesday -- has curbed the presence of those illicit groups.

Lucero said there are about 6,000 migrants in the city's network of 31 shelters -- and his recommendation to them is to use CPB One, a software application launched by the Biden administration in January and expanded after the lifting of Title 42 last week. It allows certain migrants to set up appointments to enter legally through a port of entry. "The recommendation is CBP One, the only path that is regular, orderly and safe for asylum in the United States," said Lucero.

Silva says he too is suggesting to migrants that they be patient and wait for a CBP One appointment to enter the country legally. He says he also tells them about the five-year ban on reentry into the US under Title 8.

But both in Reynosa and in Tijuana, migrants get impatient, Silva and Lucero said, because appointments are difficult to come by.

Lucero points out that the 6,000 migrants waiting in Tijuana are competing for about 240 CBP One appointments made available in the area every day.

"Don't lose your patience, use CBP One" Lucero said.