President Joe Biden has issued a sweeping executive order aimed at curbing record migrant arrivals at the US-Mexico border that have left him politically vulnerable in an election year.
Under the order, which took effect at midnight, officials can quickly remove migrants entering the US illegally without processing their asylum requests.
That will happen once a daily threshold is met and the border is “overwhelmed”, the White House said in a statement.
Rival Republicans say Mr Biden has not gone far enough, while some of the president’s Democratic allies – and the United Nations – have expressed concern.
A spokeswoman for the UN’s refugee agency said those fearing persecution should have access to safe territory.
Mr Biden spoke about the order at an event on Tuesday with several border town mayors. He said “this action will help us gain control of our border”.
The president criticised Republicans for not passing bipartisan immigration reform in Congress earlier this year – and asked left-wing critics of the new executive action to “be patient”.
“We’re wearing thin right now,” he said. “Doing nothing is not an option.”
The order – which also aims to speed up cases and ease pressure on overburdened US immigration courts – has met criticism from activists.
“It’s unfortunate that politics are driving the immigration conversation in an increasingly restrictive direction,” said Jennie Murray, president and the CEO of the National Immigration Forum.
More than 6.4 million migrants have been stopped crossing into the US illegally during Joe Biden’s administration.
The arrival numbers have plummeted this year, though experts believe that trend is unlikely to continue.
Mexican media have depicted the move as one of Mr Biden’s toughest policies, though President Andrés Manuel López Obrador sought to downplay the issue, arguing that economic and cultural exchange made a border closure “impossible”.
Authorities in Tijuana asked what would happen to asylum seekers denied entry to the US.
Shelters in the Mexican city could quickly get overcrowded, one local official warned. “We’d start seeing people on the streets, sleeping in tents”.
About a dozen advocates and Democratic lawmakers had their own press conference outside the US Capitol on Tuesday, criticising Mr Biden’s decision.
Pramila Jayapal, the chair of the Congressional Progressive Caucus, said she was “profoundly disappointed” by the executive action and called it a “step in the wrong direction”.
Others in Mr Biden’s party disagreed – including Ruben Gallego, an Arizona congressman, who said there was still “more work to do”.
The campaign for Donald Trump, Mr Biden’s Republican challenger for the presidency, earlier argued that the order “is for amnesty, not border security”.
In Tuesday’s statement after the president’s announcement, the White House said that the new order “will be in effect when high levels of encounters at the southern border exceed our ability to deliver timely consequences, as is the case today.”
Among the actions announced on Tuesday were the use of a 1952 law that allows access to the American asylum system to be restricted.
The law, known as 212(f), allows a US president to “suspend the entry” of foreigners if their arrival is “detrimental to the interests” of the country.
The same regulation was used by the Trump administration to ban immigration and travel from several predominantly Muslim countries and to bar migrants from asylum if they were apprehended crossing into the US illegally, provoking accusations of racism.
“While there’s no question the US needs to better address challenges at the border, the use of 212(f) authority is concerning,” Ms Murray said.
Ms Jayapal told the BBC she was concerned that Mr Biden’s actions could spark legal battles.
”When Donald Trump did this, the ACLU (American Civil Liberties Union) filed a lawsuit and it was declared unconstitutional, she said. “This is a different executive order. So things may be different.”
But, she added, “we are at serious risk of being in violation of our own laws”.
The Biden administration plans to defend the new policies in court from any challenges it could face from activists or Republican-led states.
It has said the restrictions will come into effect when the seven-day average for daily crossings hits 2,500.
“These actions will be in effect when the southern border is overwhelmed, and they will make it easier for immigration officers to quickly remove individuals who do not have a legal basis to remain,” the White House said.
The border will reopen to asylum seekers only when the average figure holds at 1,500 over a seven-day period – and it will then reopen to migrants two weeks later.
Other measures are aimed at quickly resolving immigration cases in court, and expedited removals for those found to have no legal basis to remain in the US.
Asylum processing at ports of entry will continue under the order.
About 1,500 asylum seekers go through the process at official crossings each day, mostly after setting up appointments using a Customs and Border Protection (CBP) app known as CBP One.
Guerline Jozef, executive director of Haitian Bridge Alliance – which works with Haitian migrants at the border – called the announcement “a direct assault on the fundamental human right to seek asylum”.
“This Trump-era policy will leave thousands of vulnerable individuals, including families, children, and those fleeing violence and persecution, without the protection and refuge they need,” Ms Jozef said.
Speaking to reporters on Tuesday, senior administration officials pushed back on comparisons with Trump-era policies, saying the new rules would only apply during periods of increased arrivals.
They said exemptions would be made for unaccompanied children and those being trafficked.
Republicans, meanwhile, have criticised the Biden border plan as an election-year ruse – and have argued for tougher action.
They argue that US laws already exist to prevent illegal immigration but are not being duly enforced by the Democratic president.
The officials and the White House have sought to lay the blame on Republicans who stood in the way of a bipartisan border security deal that failed earlier this year.
“Republicans in Congress chose to put partisan politics ahead of our national security,” the White House said.
Recently released statistics from CBP show that about 179,000 migrant “encounters” were recorded in April.
In December, by comparison, the figure spiked to 302,000 – a historic high.
Officials in the US and Mexico have said that increased enforcement by Mexican authorities is largely responsible.
The decline in migrant crossings at the US border comes at a politically fraught time for President Biden.
Polls show that immigration is a primary electoral concern for many voters in the presidential election in November.
A Gallup poll at the end of April suggested that 27% of Americans view immigration as the most important issue facing the country, topping the economy and inflation.
A separate poll conducted in March by the Associated Press and NORC Center for Public Affairs Research indicated that two-thirds of Americans now disapprove of Mr Biden’s handling of the border, including about 40% of Democrat voters. – BBC
By Bernd Debusmann Jr