The attorney for Stormy Daniels, the pornographic actor who claims to have had an affair with Donald Trump, said Daniels had been threatened with physical harm.

Attorney Michael Avenatti declined to say whether or not the threats had come from the president, in an interview on Friday about the alleged affair.

Towards the end of a 12-minute interview on MSNBC’s Morning Joe co-host Mika Brzezinski asked if Daniels, whose given name is Stephanie Clifford, “had been threatened in any way”.

Avenatti said: “Yes.”

Brzezinski then asked: “Was she threatened with physical harm?”

Avenatti replied: “Yes.”

He declined to answer ensuing questions about whether Clifford’s life had been threatened or if the president had issued any of the threats.

“I’m not at liberty to discuss it,” Avenatti said. “You can ask it 17 different ways. I’ll give you the same answer.”

Avenatti said details of the threat, and the alleged affair that Clifford has said took place in 2006 and 2007, would be made public in an interview on CBS’s 60 Minutes on 25 March.

Earlier this month, Clifford sued Trump and his longtime personal lawyer, Michael Cohen, claiming they sought to silence her from speaking about her relationship with Trump. The lawsuit seeks to void a non-disclosure agreement Clifford signed before the presidential election in 2016. A court hearing is set for 12 July in Los Angeles.

Cohen said he had used a line of credit based on the value of his own home to gather $130,000 to pay Clifford in a personal capacity. There is no proof that Trump knew about or approved the payment.

Trump has not spoken about the controversy and, through aides, has denied the relationship.

The first question at Friday’s White House press briefing was about the claim that Daniels had been physically threatened to stay silent and whether Trump was concerned.

Press secretary Sarah Sanders said: “Obviously we take the safety and security of any person seriously, certainly would condemn anyone threatening any individual, but I have no knowledge of that situation and would refer you to the president’s outside personal attorneys.”

Asked if Trump had anything to say about the claim, Sanders replied: “I haven’t spoke with him about that specifically.”

Cohen has denied that Clifford was paid to keep quiet about the alleged affair.

On Monday, Cliffored offered to return the money if she could speak freely.

The payment to Clifford was known about before the election, but it was not until January 2018 that a celebrity magazine released the transcript of a previously unpublished 2011 interview in which Clifford described an encounter with Trump.