Washington DC - Vice President JD Vance on Wednesday announced a freeze on funding for medical benefits for the state of Minnesota, a day after President Donald Trump tapped him to lead a "war on fraud."

Minnesota has been in the Republican administration's crosshairs over claims of benefit fraud, which it has used to fuel racists attacks on the Somali community.

"We have decided to temporarily halt certain amounts of Medicaid funding that are going to the state of Minnesota," Vance told a news conference.

The federal government would freeze $259 million in payments to Minnesota, said Mehmet Oz, the celebrity TV doctor who is now Trump's administrator for the Centers for Medicare and Medicaid Services.

The freeze is almost certain to be challenged in court, as have previous attempts by the administration to withhold federal funds to states.

Trump announced in his State of the Union address on Tuesday that he was appointing Vance to the new fraud role as he railed against Minnesota in particular.

The Trump administration has alleged without evidence that public benefits fraud is widespread in the state's Somali community as a whole, while Trump himself has repeatedly lashed out at Somali immigrants, including in his speech.

Minnesota has the largest Somali community in the US and has seen its major cities subjected to an occupation by federal immigration agents who have terrorized local communities and killed two US citizens in the past weeks.