WASHINGTON—The Supreme Court on Friday voiced skepticism of TikTok’s challenge to a federal law requiring the China-based social-media app to shut down or find new owners by Jan. 19. The court heard oral arguments on the constitutionality of the bipartisan bill President Biden signed last April that classifies the app,

A majority of the justices appeared more concerned about the national security implications of the popular app’s Chinese ownership than about the restrictions on free speech the law would impose.

Congress labeled the app’s Chinese ownership a national security risk and passed a law that would ban the social media platform unless it was sold. TikTok and creators say that violates their free speech rights.