The US State Department said it would deny visas to five people, including a former EU commissioner, for seeking to "coerce" American social media platforms into suppressing viewpoints they oppose.

"These radical activists and weaponized NGOs have advanced censorship crackdowns by foreign states - in each case targeting American speakers and American companies," Secretary of State Marco Rubio said in a statement.

Thierry Breton, the former top tech regulator at the European Commission, suggested that a "witch hunt" was taking place.

Breton was described by the State Department as the "mastermind" of the EU's Digital Services Act (DSA), which imposes content moderation on social media firms.

However, it has angered some US conservatives who see it as seeking to censor right-wing opinions. Brussels denies this.

Breton has clashed with Elon Musk, the world's richest man and owner of X, over obligations to follow EU rules.

The European Commission recently fined X €120m (£105m) over its blue tick badges - the first fine under the DSA. It said the platform's blue tick system was "deceptive" because the firm was not "meaningfully verifying users".

In response, Musk's site blocked the Commission from making adverts on its platform.

Reacting to the visa ban, Breton posted on X: "To our American friends: Censorship isn't where you think it is."

Clare Melford, who leads the UK-based Global Disinformation Index (GDI), was also listed.

US Undersecretary of State Sarah B Rogers accused the GDI of using US taxpayer money "to exhort censorship and blacklisting of American speech and press".

A GDI spokesperson told the BBC that "the visa sanctions announced today are an authoritarian attack on free speech and an egregious act of government censorship".

"The Trump Administration is, once again, using the full weight of the federal government to intimidate, censor, and silence voices they disagree with. Their actions today are immoral, unlawful, and un-American."

Imran Ahmed of the Center for Countering Digital Hate (CCDH), a nonprofit that fights online hate and misinformation, was also handed a ban.

Rogers called Mr Ahmed a "key collaborator with the Biden Administration's effort to weaponize the government against US citizens".

The BBC has reached out to the CCDH for comment.

Also subject to bans were Anna-Lena von Hodenberg and Josephine Ballon of HateAid, a German organisation that the State Department said helped enforce the DSA.

In a statement to the BBC, the two CEOs called it an "act of repression by a government that is increasingly disregarding the rule of law and trying to silence its critics by any means necessary".

"We will not be intimidated by a government that uses accusations of censorship to silence those who stand up for human rights and freedom of expression," they added.

Rubio said that steps had been taken to impose visa restrictions on "agents of the global censorship-industrial complex who, as a result, will be generally barred from entering the United States".

"President Trump has been clear that his America First foreign policy rejects violations of American sovereignty. Extraterritorial overreach by foreign censors targeting American speech is no exception," he added.