A U.S. judge on Monday blocked the Trump administration's plan to relocate the FBI headquarters to a federal office building in Washington, D.C., determining that the move was unlawful. The decision halts the administration's attempt to repurpose the Ronald Reagan Building for the FBI.

U.S. District Judge Theodore D. Chuang, an appointee of former President Barack Obama, ruled that the proposed move was "not in accordance with law." The ruling prevents the Trump administration from moving the FBI into the Reagan Building, renovating it for the agency, or reallocating funds designated for the project.

The FBI's current headquarters, the J. Edgar Hoover Building, was constructed in 1975 and has faced criticism for its disrepair, with protective nets surrounding the structure to prevent debris from falling.

The legal challenge was initiated by the state of Maryland and Prince George's County. According to Maryland Attorney General Anthony Brown, the state and county had committed over a decade of work and pledged hundreds of millions of dollars toward establishing the FBI headquarters in Greenbelt, Maryland. The Greenbelt site had been selected during the Biden administration, overriding a previous decision that favored a location in Virginia.

Officials from the Department of Justice and the FBI did not immediately respond to requests for comment following the ruling.