In a court filing, prosecutors said they had "discussed the merits of the case" with Kelly's defense counsel. "Upon reflection of the facts currently known to the government, the government believes that dismissal without prejudice at this time serves the interests of justice," they wrote.
The filing did not offer details on why the government wants the case dismissed.
A spokeswoman for the Justice Department did not immediately respond to a request for comment, and a defense attorney for Kelly declined immediate comment.
Kelly was one of more than 400 people to face charges in connection with the riots on Jan. 6, in which throngs of former President Donald Trump's supporters stormed the Capitol in a failed bid to stop Congress from certifying President Joe Biden's victory.