The department reported faster processing for migrants in custody on the border, more temporary detention tents, staffing surges and increased criminal prosecutions of smugglers, noting progress on a plan announced in April.
But the seven-page document dated Tuesday included no major structural changes amid unusually large numbers of migrants entering the country.
More are expected with the end of Title 42 authority, under which migrants have been denied rights to seek asylum more than 2.5 million times on grounds of preventing the spread of COVID-19.
A federal judge in Washington ordered Title 42 to end December 21 but Republican-led states asked an appeals court to keep it in place.
The Biden administration has also challenged some aspects of the ruling, though it doesn't oppose letting the rule lapse next week. The legal back-and-forth could go down to the wire.
Homeland Security Secretary Alejandro Mayorkas travelled this week to El Paso, Texas, which witnessed a large influx on Sunday after becoming the busiest corridor for illegal crossings in October.
El Paso has been a magnet for Venezuelans, Nicaraguans, Cubans, Colombians, Ecuadoreans and other nationalities.
The geographic shift to Texas' westernmost reaches was likely a result of smugglers' calculations on the best route, said Nicolas Palazzo, an attorney at Las Americas Immigrant Advocacy Center in El Paso.
Like other advocacy groups that work directly with directly with Homeland Security, Palazzo said he has had no conversations with the department about post-Title 42 planning. One key question: How will authorities process migrants who have long been waiting to seek asylum?
US Rep. Henry Cuellar, D-Texas, said Customs and Border Protection officials told him Wednesday that about 50,000 migrants are believed to be waiting to cross once Title 42 is lifted.
Authorities plan to admit those seeking asylum who go through ports of entry but return to Mexico those who cross illegally between official crossings, Cuellar said in an interview.
It was unclear how they will return nationalities that Mexico won't accept — like Cubans and Nicaraguans — and are difficult to send home due to strained diplomatic relations and other challenges.
Administration officials are developing additional measures, which Cuellar said they would not disclose.
“I think the first week is going to be a little bit of chaos,” he said.
US officials in El Paso are currently exempting 70 migrants daily from Title 42, said Palazzo, who questioned how officials will handle more people.
Unless they raise processing capacity significantly, migrants who go through official crossings may be told to wait a year or so for an appointment, said Palazzo.
“Realistically can they tell me with a straight face that they expect people to wait that long?”
In its latest assessment, CBP said government agencies “have been managing levels well beyond the capacity for which their infrastructure was designed and resourced, meaning additional increases will create further pressure and potential overcrowding in specific locations along the border.”
More single adults and families with young children may be released into communities with instructions to appear in immigration court without help of nongovernmental groups or financial sponsors, the department said.
The department didn't indicate how many migrants may cross the border when Title 42 ends. Earlier this year, they expected as many as 18,000 a day, a staggering number.
In May, migrants were stopped an average of 7,800 times a day, the peak month of Joe Biden's presidency.
In the fiscal year that ended Sept. 30, migrants were stopped 2.38 million times, up 37 per cent from 1.73 million times the year before. The annual total surpassed 2 million for the first time.
The numbers reflect deteriorating economic and political conditions in some countries, relative strength of the US economy and uneven enforcement of Trump-era asylum restrictions.