“The officer asked me to hand over my badge. He said that it was disabled,” MS NOW reporter Akayla Gardner said. “I asked why I was not able to get inside. He said it was above him.”

Gardner added that while her and her colleague’s badges were disabled, an MS NOW producer was still able to scan her badge to get in, though she was not given an explanation as to why the producer’s badge still worked.

CNN reporter Betsy Klein said a Secret Service agent told her her badge had been deactivated.

Later on Saturday morning, Politico said its reporter Cheyenne Haslett was denied entry and Secret Service revoked her pass.

All three outlets have spoken out against the decision, accusing Trump of violating their constitutional rights to free speech and freedom of the press.

An MS NOW spokesperson said in a statement that the White House “belongs to the American people and the decisions made inside are funded by our tax dollars”.

MS NOW said it “intends to take any and all steps necessary to defend our First Amendment rights and the essential role of independent journalism in our democracy”.

Politico Editor-in-Chief Jonathan Greenberger said in an internal email, shared in the outlet’s Playbook newsletter, that the company stands by its reporters and will “vigorously defend” their First Amendment rights.

And CNN said, “We have a right under the US Constitution to do our reporting without hindrance or interference from the government and this ban is an illegal assault on this fundamental right.”

In his announcement, Trump did not mention specific stories or reporting from the three outlets that prompted the move, but later said “it’s really just cumulative stories over the last few years”.

Trump added that there “may be others to join them”, but has not given a directive banning additional news outlets. When later asked by a reporter what he meant by others to come, Trump responded: “Others to come in terms of fake news? Well, you know, the New York Times is fake news, the Washington Post is fake news.”

The White House Correspondents Association (WHCA) – the independent, non-profit group that represents journalists who cover the US presidency – called on the administration “to immediately restore” access to the journalists and accused it of violating the First Amendment.

“The implications extend beyond these organizations: a standard used to exclude one news outlet because of its coverage could be applied to any outlet in the future,” said WHCA President Jacqui Heinrich, who works for Fox News.

Heinrich said that the Americans, through a free and independent press, must be able to scrutinise those elected in their coverage “regardless of whether government officials view it favorably”.

“That’s why courts have repeatedly held that once the White House provides access to journalists, it cannot deny that access arbitrarily or based on the content of their reporting.”

Several groups dedicated to the freedom of the press have called Trump’s White House ban illegal and unconstitutional.

A major group that provides legal services to the media – the Reporters Committee for Freedom of the Press – said it expected Trump’s ban to be struck down quickly by the courts because it was “flatly unconstitutional”.

“The First Amendment is clear that once the White House invites in some journalists, it can’t ban others because it doesn’t like their reporting,” said Bruce Brown, president of the Reporters Committee for Freedom of the Press, which provides legal services to the media.

It’s the latest in a series of moves by the administration to target media outlets Trump says are critical of him, including legal action against US and international outlets like The New York Times, The Wall Street Journal, and the BBC.

Some of the lawsuits have resulted in media organisations agreeing to pay multimillion dollar settlements. Trump’s lawsuit against the BBC is ongoing.

Additional reporting from Bernd Debusmann Jr and Max Matza.