US president Joe Biden's administration will block migrants from claiming asylum at the US-Mexico border until attempted crossings fall under new actions rolled out on Tuesday.
The asylum ban came into effect on Wednesday, barring any legal challenges that might block it.
What does the Biden asylum ban do?
The new asylum ban allows authorities to quickly deport or send back to Mexico migrants who cross the US-Mexico border illegally without the chance to claim asylum, but they only take effect when migrant arrests surpass 2,500 per day for a week.
Border arrests averaged 4,300 per day in April, the most recent statistics publicly available. US officials said on Tuesday that arrests remained high enough for restrictions to go into effect immediately.
The restrictions will stay in place until arrests drop below an average of 1,500 per day for three weeks. The last time crossings fell to that level was in the early months of the Covid-19 pandemic in July 2020 when global travel was at historic lows.
Will these measures 'close' the border?
No. The restrictions apply to migrants crossing between ports of entry, but access will not be blocked for people who seek an appointment to approach a legal port of entry through a government-run cell phone app. Others who have applied from abroad to enter through various parole programs started by the Biden administration or temporary work visa holders will be allowed in.
The ban will also not apply to unaccompanied minors or people who face serious medical or safety threats and victims of trafficking, administration officials said.
Legal trade and travel across the US-Mexico border will not be affected.
How will this work in practice?
Key operational questions about how the asylum ban will be implemented remained unclear, including how the administration would quickly deport migrants from far-away and uncooperative countries and how many non-Mexican migrants Mexico would accept under the new enforcement regime.
Local officials and shelter directors in Tijuana, Mexico - across from San Diego, California - said migrants could get stuck in Mexico where capacity to house them safely is limited.
Will the ban be challenged in court?
Almost certainly. The American Civil Liberties Union said it intends to sue. The ACLU and other civil and immigrant rights groups challenged similar asylum bans during issued by former president Donald Trump.
Why is Biden doing this now?
Mr Biden has pushed unsuccessfully for months to pass a Senate bill that would toughen border security, including with a provision that resembles his latest moves by executive action. The bill was crafted by a bipartisan group of senators, but Republicans rejected it after Mr Trump came out in opposition.
Immigration is a key issue in the upcoming US presidential elections in November when Mr Biden will be facing Mr Trump again in a rematch of the 2020 race. When it comes to immigration policy, registered voters prefer Mr Trump to Mr Biden by a 17 percentage point margin, according to a Reuters/Ipsos poll conducted in mid-May.
Border crossings have dropped in recent months, which the Biden administration credits in part to increased enforcement by Mexico. Still, Mr Biden in his asylum ban proclamation said "the factors that are driving the unprecedented movement of people in our hemisphere remain, and there is still a substantial and elevated level of migration that continues to pose significant operational challenges".
How are Republicans and Democrats reacting?
Republicans broadly oppose Mr Biden's immigration policies and many spoke out against the last asylum restrictions, saying they were politically motivated and not sufficient.
In advance of the announcement, Mr Trump's campaign issued a statement criticising Mr Biden for high levels of illegal immigration and said the move to exempt unaccompanied minors would encourage child trafficking.
Mr Trump posted on Truth Social that the move was "all for show" because the two candidates are scheduled to debate on June 27th and ripped Biden programmes that allow migrants to enter legally and obtain work permits.
Democrats were split on the asylum ban, with more liberal lawmakers criticising Mr Biden and moderates praising him.
Alex Padilla, a Democratic US senator from California, said Mr Biden "undermined American values" and that the order would lead to "people with legitimate asylum claims being prevented from seeking safety and returned to harm".
On the flip side, US representative Ruben Gallego, a Democrat running for a US Senate seat in Arizona, called the move "a step in the right direction".
What's next?
On a call with reporters on Tuesday, US officials declined to provide details on how they would handle the increased number of deportations or how they would deal with families, who are currently not detained after being arrested at the border.
