US president Donald Trump’s personal lawyer has explained that was not trying to make an existential point about the meaning of veracity when he declared “truth isn’t truth”.

Rudy Giuliani’s puzzling statement on NBC’s Meet the Press, following a similar comment by another adviser to Mr Trump last year about “alternative facts”, suggested that people in Mr Trump’s orbit might be denying the existence of reality.

Mr Giuliani said his intent was more mundane: to make the case that having Mr Trump sit down for an interview with special counsel Robert Mueller’s team on alleged Russian collision would not accomplish much because of the conflicting nature of witnesses’ recollections.

Mr Giuliani tweeted: “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 had told Meet the Press host Chuck Todd that Mr Trump might “get trapped into perjury” if he were interviewed by the special counsel’s Russia investigation.

The former mayor of New York City said: “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.”

When Mr Todd replied: “Truth is truth,” Mr Giuliani responded: “No, it isn’t truth. Truth isn’t truth.”