Donald Trump’s attorney Rudy Giuliani has attempted to clarify his “truth isn’t truth” comment, made as he tried to explain why the US president should not testify for special counsel Robert Mueller’s investigation into Russian election meddling.

Taking to Twitter, the former New York City mayor wrote: “My statement was not meant as a pontification on moral theology, but one referring to the situation where two people make precisely contradictory statements, the classic ‘he said, she said’ puzzle. Sometimes further inquiry can reveal the truth other times it doesn’t”.

Mr Giuliani was widely mocked after his appearance on NBC’s Meet the Press when he said he was not going to be rushed in having Mr Trump testify before Mr Mueller “so he gets trapped into perjury”.

The special counsel is leading the investigation into alleged collusion between Mr Trump’s 2016 campaign team and Russian officials.

The president has said he is willing to speak with Mr Mueller’s team for an interview, while denying any collaboration with Moscow and repeatedly attacking the probe as illegitimate.

His legal team have prevented him from doing so because they believe the special counsel’s investigators could take what Mr Trump says, if it differs from what others have laid out, as a lie.

Asked about the probe by Meet the Press host Chuck Todd, Mr Guiliani said: “Look, I am not going to be rushed into having [Donald Trump] testify so that he gets trapped into perjury. And when you tell me that, you know, he should testify because he’s going to tell the truth and he shouldn’t worry, well that’s so silly because it’s somebody’s version of the truth. Not the truth.”

Mr Todd replied: “Truth is truth.”

But Mr Giuliani insisted: “No, it isn’t truth. Truth isn’t truth. The president of the United States says, “I didn’t …”

Mr Todd said: “Truth isn’t truth?”

Mr Giuliani responded: “No, no.”

Putting his hand to his forehead, Mr Todd said: ”This is going to become a bad meme.”

Mr Giuliani was widely mocked on social media for the comments. Preet Bharara, a Democrat who was fired as federal prosecutor by the Trump administration, suggested “truth isn’t truth” would not sound convincing in a trial.

His comments came after a jury retired to reach a verdict in the first trial resulting from the Russia investigation. Mr Trump’s former campaign manager Paul Manafort is accused of 18 counts of tax evasion and bank fraud. The jury is currently on its fourth day of deliberations.

Former campaign deputy Rick Gates has already pleaded guilty to similar counts of fraud and lying to the FBI, respectively, while former National Security Adviser Michael Flynn and campaign foreign affairs aide George Papadopoulos have also pleaded guilty to lying to the FBI during the course of the investigation.