Illegal crossings at the US-Mexico border have hit the lowest level in over half a century, according to federal data obtained by the BBC's US partner CBS News.

In fiscal year 2025, which spanned four months of former President Joe Biden's administration, US Border Patrol agents stopped 238,000 migrants crossing the southern border illegally, the Department of Homeland Security figures suggest.

During Trump's first eight months in office, there have been fewer than 9,000 illegal crossings recorded each month, CBS reported.

It is the lowest number of apprehensions since 1970, when border patrol agents stopped 202,000 people crossing the US-Mexico border unlawfully.

"The numbers demonstrate progress on border security," said Jennie Murray, president and chief executive of the National Immigration Forum, adding that both parties and the White House need to work on passing immigration legislation.

Patrol agents made over half of the apprehensions at the border during the first three months of the 2025 fiscal year, which ran from October 2024 to September 2025, during Biden's tenure, according to the preliminary data.

The apprehensions indicate the number of times border police stopped and processed migrants entering the country illegally at official ports of entry, which may include people who attempted to cross the border more than once after being stopped.

US Customs and Border Patrol has said about 11 million border encounters were recorded over the course of Biden's four years in office.

White House spokeswoman Abigail Jackson told the BBC that the latest border figures showed Trump was delivering on his pledge to secure the border.

"As a result, Americans are safer - unvetted criminal illegal aliens and dangerous drugs are no longer pouring over our border unchecked," she said in an emailed statement.

"And for all the Democrats who claimed it was impossible to secure the border or that they needed new policy, turns out all we needed was a new President."

After taking office in January, Trump established a host of immigration-related executive orders, including deploying additional troops to the border, ending asylum requests and expanding Immigration and Customs Enforcement's (ICE) ability to arrest and detain illegal migrants on US soil.

The Republican president has also tried to end birthright citizenship in the US.

Trump has also pledged to deport millions of undocumented immigrants during his time in office. In recent months, the president's administration has conducted immigration raids in major US cities, including Los Angeles and Chicago.