US President Donald Trump will take a victory lap Wednesday as he signs a bill cracking down on migrant criminal suspects -- his first piece of legislation since he returned to power vowing a blitz on illegal immigration.

The ceremony at the White House comes as Trump faces pushback over his broader plans to overhaul the government, including a funding freeze that caused chaos and an offer of a severance package to federal workers.

The Laken Riley act -- which orders the pre-trial detention of undocumented migrants charged with theft and violent crimes -- is named for a 22-year-old student murdered by a Venezuelan man who was wanted for shoplifting.

The Republican-led US Congress passed the law just two days after Trump's inauguration on January 20, with some Democrats also joining in after hardening US attitudes on migration proved crucial in Trump's election win.

"President Trump has used every lever of his executive power to ensure that we can secure the border," White House Press Secretary Karoline Leavitt told Fox News on Wednesday.

Trump repeatedly spotlighted Laken Riley's case during his election campaign as he railed against undocumented migrants, blaming them for "poisoning the blood" of the country.

Jose Antonio Ibarra, 26, a Venezuelan with no papers, was convicted of murdering the nursing student in 2024 after she went missing on her morning run near the University of Georgia in Athens.

Ibarra had been arrested and released twice before, including when he crossed the Mexican border in 2022.

Trump has since launched what his second administration is casting as a major crackdown on illegal migration, trumpeting immigration raids and arrests and deportations on military aircraft.

His administration said on Wednesday it had evoked an extension of the protected status for more than 600,000 Venezuelans that had allowed them to remain in the United States.

Trump has made the issue a priority on the international stage too, threatening Colombia with sanctions and massive tariffs for turning back two planeloads of deportees, before Bogota backed down.

'Option to resign'

The Republican president has meanwhile launched a fully fledged bid to overhaul the US government, vowing to force federal employees to back his right-wing political goals or face retribution.

Potentially trillions of dollars in federal grants, loans and other aid faced possible suspension by the White House, although a federal judge suspended the order shortly before it was to take effect Tuesday afternoon.

Trump hours later unveiled an even more radical move, offering most federal workers the option to leave their jobs in exchange for eight months severance, plunging the lives of US civil servants into disarray.

The White House denied accusations of a purge of Trump's opponents.

"Absolutely false. This is a suggestion to federal workers that they have to return to work," Leavitt told reporters, referring to Trump's bid to make all federal employees return to full-time office work.

"If they don't then they have the option to resign and this administration is very generously offering to pay them for eight months."