WASHINGTON (AP) — Apple says a Justice Department antitrust lawsuit accusing it of engineering an illegal monopoly in smartphones in the U.S. is “wrong on the facts and the law.”

The lawsuit was filed Thursday in federal court in New Jersey.

The suit alleges Apple uses its control over the iPhone to engage in an “illegal course of conduct.”

The lawsuit is the latest example of the Justice Department’s approach to aggressive enforcement of federal antitrust law that officials say is aimed at ensuring a fair and competitive market.

Apple has defended the digital fortress known as its walled garden as a feature prized by consumers who want to protect their personal information.