Former U.S. President Donald Trump used his first public appearance since his federal indictment to ratchet up attacks on the Justice Department, accusing prosecutors of a politically motivated campaign to keep him from the White House.

Speaking on Saturday at Georgia's state Republican convention, Trump alleged that President Joe Biden, a Democrat, orchestrated the criminal charges in order to undermine his main political rival's presidential campaign, as well as to distract from federal and congressional investigations into Biden's son. The Justice Department maintains that all its investigative decisions are made without regard to partisan politics, and Biden has said he would not get involved in the Trump probe.

"The ridiculous and baseless indictment of me by the Biden administration's weaponized department of injustice will go down as among the most horrific abuses of power in the history of our country," Trump said.

His remarks came one day after prosecutors unsealed a 37-count indictment against him, alleging he mishandled classified documents that included some of the country's most sensitive security secrets after leaving the White House in 2021.

Prosecutors allege the former president held on to materials, including documents about the U.S. nuclear program and domestic vulnerabilities to a potential attack, that he knew he should not have retained.

The indictment of a former U.S. president on federal charges is unprecedented in American history and came as Trump is the clear front-runner for the Republican presidential nomination next year.

Trump told Politico on Saturday that he would continue running for president even if he were convicted. The former U.S. president is due to make a first appearance in the case in a Miami court on Tuesday.

(With input from Reuters)