X logo, EU flag and Judge gavel are seen in this illustration taken, August 6, 2024. REUTERS/Dado Ruvic/Illustration

WASHINGTON, Dec 8 (Reuters) - U.S. President Donald Trump on Monday called a fine imposed on Elon Musk's social media company X by European Union tech regulators "a nasty one" and said he did not understand how they could justify the move.

X was fined 120 million euros ($140 million) by EU tech regulators last week for breaching online content rules.

"Europe is going in some bad directions," Trump told reporters at a White House event, saying he expected to get a full report on the EU fine later on Monday.

"I don't see how they can do that," Trump said. He said Musk had not called him to ask for help on the issue.

"Europe has to be very careful," he added.

Last week, Musk dismissed the penalty on his platform, replying "Bullshit" under a European Commission post announcing the fine and reposting messages criticizing the decision.

"Freedom of speech is the bedrock of democracy. The only way to know what you are voting for," he wrote.

U.S. officials, including Secretary of State Marco Rubio and FCC Chairman Brendan Carr, denounced the move as an attack on American companies.

EU regulators said X violated transparency obligations, including failing to provide researchers access to public data, maintaining an incomplete advertising repository, and using deceptive design for its blue checkmark verification system.

EU tech chief Henna Virkkunen defended the fine as proportionate and stressed the DSA "has nothing to do with censorship". The European Commision said its laws do not target any nationality and it is merely defending its digital and democratic standards.

TikTok, charged in May for failing to maintain a public ad repository to help detect scam ads, avoided a fine by pledging improvements to its ad library and urged regulators to enforce the rules consistently across platforms.

(Reporting by Nandita Bose, Andrea Shalal and Kritika Lamba; Editing by Leslie Adler and Krishna Chandra Eluri)