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" to undo the policies of Donald Trump.

And since taking office, the Democrat has created a taskforce to reunify migrant children with their families, paused construction of the border wall, and called for reviews of legal immigration programmes terminated by his predecessor.

He has also presided over a record-breaking influx of arrivals to the US southern border, including hundreds of unaccompanied children who are being held in US immigration detention facilities.

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

In April, Mr Biden stunned his supporters by announcing plans to only allow 15,000 refugees into the US in 2021. The annual refugee cap was set by Mr Trump the year before, and was an historic low.

Mr Biden soon reversed course following a backlash, and raised the number to 62,500 refugees. He also pledged to increase the refugee cap in 2022 to 125,000.

About 110,000 refugees were admitted to the US in the last year of Barack Obama's final presidential term.

Mr Biden also called for more refugees to come from Africa, the Middle East and Central America, and for an end to restrictions on resettlements from Somalia, Syria and Yemen.

Over 178,000 people were arrested crossing the border in April, the most ever recorded in a single month.

Some 16,933 were children who were not travelling with their legal guardian encounters in April, down slightly from March figures, according to US Customs and Border Protection (CBP) data.

The previous monthly high of 11,000 lone children recorded in May 2019 came during Mr Trump's presidency.

The influx of minors swiftly overwhelmed migration processing facilities and saw thousands of children put in CBP facilities originally designed to hold adults.

Mr Biden's critics have suggested that holding children in those detention facilities harkens back to a Trump-era policy, the major change being that children are held for less time under President Biden.

The numbers of children held by CBP dropped by 88% by early May, as the children were transferred to the Department of Health and Human Services for temporary resettlement as their immigration case is heard by the courts.

Unlike under Mr Trump, the Biden White House has not sought to crackdown on families arriving together by separating children from parents.

Mr Trump's so-called "zero tolerance" policy saw families divided by US authorities, in some cases with parents being deported back to their home countries without their children. The policy was reversed and some families - but not all - reunited.

A taskforce enacted by Mr Biden in January to reunite the remaining families began to do so in the US in early May. The panel estimates that about 1,000 families remain separated.

On Mr Biden's first day in office, the Department of Homeland Security (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 programme - since it was introduced in January 2019.

In February, 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.

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

The president has proposed a major immigration bill that would offer an eight-year pathway to citizenship to the estimated 11 million undocumented people living 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.

As part of his efforts to curb immigration, Mr Trump had sought to end the programme in 2017, calling it unconstitutional. His efforts were ultimately blocked by the courts.

Mr Biden's pro-immigration policy - which would greatly increase both family-based and employment-based legal immigration - is facing staunch opposition in Congress, among Republicans and some moderate Democrats.

After coming into office vowing not to build "another foot" of Mr Trump's border wall, Mr Biden signed an order on his first day in office to pause all wall construction and to end the national emergency declaration on the southern border.

He later ordered that military funds Mr Trump had tapped for the project be re-allocated, leading to a Republican-requested inquiry into whether Mr Biden had inappropriately re-directed congressionally approved funds.

Property owners near the border have complained that despite the pause, the government is still seeking to seize border lands for future construction using a process known as eminent domain.

Dozens of eminent domain cases brought by the federal government remain open and could take years for the courts to decide.

Some wall construction sites remain abruptly abandoned, with building materials strewn about, as construction had been ongoing right up until the moment of Mr Biden's order to halt.

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.

On Covid, Mr Biden has so far left a Trump-era emergency policy in place. The policy allows US authorities to automatically 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 unaccompanied migrant children or teenagers.

The Biden administration has defended the Trump-era policy in courts, where civil rights groups have sued to have the US asylum system continue processing claims.

Without using the rhetoric of his predecessor, Mr Biden has called for migrants to not attempt the dangerous journey to the US in an effort to stem the recent influx.

"I can say quite clearly: don't come over," he said in an ABC News interview in March.

"We're in the process of getting set up, don't leave your town or city or community," he added.