What is Biden doing differently at US border?

On the campaign trail, Joe Biden made sweeping promises to reform US immigration, vowing to "take urgent action" and undo the policies of Donald Trump.

And since taking office, the Democrat has ordered the reunification of migrant children with their families, ended construction of the border wall and called for reviews of legal immigration programmes terminated by his predecessor. But for those seeking entry at the US southern border, the Biden administration has asked for patience, saying it needs time to prepare for an influx of arrivals.

"We're not saying 'don't come,'" Mr Biden's top homeland security official Alejandro Mayorkas said this week. "We're saying 'don't come now.'"

Here's a look at what Mr Biden has - and hasn't - done so far, and how it differs from Mr Trump.

Depends who you ask, but numbers are definitely rising.

In January, the month that Mr Biden took office, 5,871 unaccompanied children crossed the border - up from 4,995 in December - according to data from US Customs and Border Protection (CPB).

And CPB reported an average of nearly 3,000 arrests per day in January, compared with an average of about 1,800 arrests in January 2020.

But the Biden administration has disputed that there is yet a "crisis" at the border.

"The answer is no," Secretary of Homeland Security Alejandro Mayorkas told a reporter this week. "I think there is a challenge at the border that we are managing."

And the uptick is still modest compared with 2019, when border officials apprehended more than 76,000 unaccompanied minors.

But pressure is building at the southern border, and some reports suggest the numbers are on pace to overtake the record highs of that year.

Behind closed doors, Mr Mayorkas's comments suggest he might agree. He told senior officials last month to "prepare for border surges now" according to emails obtained by the Washington Times.

And this week Russell Hott, a senior official with Immigration and Customs Enforcement (ICE) told staff in an email that arrivals of unaccompanied minors and families at the US border this year is expected to be the "the highest numbers observed in over 20 years," according to the Washington Post newspaper.

Migrants cross the border in one of two ways.

Those who "have suffered persecution or fear that they will suffer persecution" in their home country are eligible for asylum when they present themselves at a port of entry for admission into the US.

Others may evade immigration inspectors and border patrol by hiding in vehicles or travelling undetected across unprotected - and typically treacherous - sections of the US-Mexico border.

According to the Pew Research Center, at least 40% of unauthorised migrants in the country entered legally on short-term visas and overstayed.

Yes.

While in office, Donald Trump faced outrage over the conditions inside border facilities holding minors. Images from inside the detention centres showed children overcrowded in metal cages, others sleeping under foil blankets.

Some of these Trump-era facilities - now renovated and upgraded - are being used again.

Mr Biden has so far left a Trump-era Covid-19 emergency policy in place, which allows US authorities to expel almost all undocumented migrants seeking entry - bypassing normal immigration laws and protections.

But unlike Mr Trump, Mr Biden has decided not to refuse entry to migrant children or teenagers.

Now, some 200 migrant children are crossing the border each day, and thousands of minors have been detained in holding facilities at the country's southwest border in recent weeks.

On Monday, Secretary Mayorkas said minors were held by the Department of Homeland Security (DHS) for "processing" for a maximum of 72 hours.

The children are then turned over to the Department of Health and Human Services (HHS) "to address the needs of that child", Mr Mayorkas said, including vetting the sponsor families who will house the children while their cases are adjudicated in immigration court. Children and teens are held by HHS for a month on average, he said.

Human rights groups and members of Mr Biden's own party have criticised the decision to hold children in government custody for the weeks or months it takes to match them with sponsors.

Some of Mr Biden's critics have suggested the process harkens back to Trump-era policy, the major change being that children are held for less time under President Biden.

Mr Mayorkas dismissed a comparison to Mr Trump's immigration programs as "absolutely inaccurate", saying his department was acting in the "best interest" of the migrant children.

But some advocates say that with most children arriving with plans to reunite with sponsors - typically friends or family - they should be transferred immediately to their care.

And according to preliminary plans obtained by US media, such a system may already be in the works.

The Biden administration is reportedly rushing to convert its existing facilities into "reception centres", meant to rapidly process migrant families with the goal of releasing them into the US within 72 hours of arrival.

The proposal would replace long-term detention with Ellis Island-style processing, allowing migrants to travel to US sponsors before completing asylum screenings. The reports, from the Washington Post and the San Antonio Express, suggest a major overhaul of the US immigration system.

On Mr Biden's first day in office, DHS suspended a controversial Trump-era policy that forced asylum seekers to wait in Mexico for their US immigration hearings.

About 70,000 migrants were enrolled in the Migrant Protection Protocols (MPP) - informally known as the Remain in Mexico program - since it was introduced in January 2019.

Last month, the Biden administration began to gradually process these tens of thousands of people waiting in Mexico, allowing them into the US while their cases are heard.

Still, Biden officials have stressed that migrants should not attempt to enter the US right now, saying more time is needed to rebuild the asylum systems they say were dismantled by Mr Trump.

"A message to individuals who are thinking of coming to our border: they need to wait," Mr Mayorkas said on Monday. "It takes time to rebuild the system from scratch."

Biden's administration has taken several steps to reform the country's legal immigration system.

He has proposed a major immigration bill that would offer an eight-year pathway to citizenship to the estimated 11 million undocumented people in the country.

The legislation would also provide permanent protection for young migrants in the Deferred Action for Childhood Arrivals (Daca) program, known as Dreamers.

The aggressively pro-immigration policy - which would greatly increase both family-based and employment-based legal immigration - will face staunch opposition in Congress, among Republicans and some moderate Democrats.