PRESIDENT Donald Trump has given what may be his most bizarre press conferences to-date following a speech to the UN that drew laughs from world leaders.

Among a series of strange boasts the president assured reporters that: "China has total respect for Donald Trump and for Donald Trump's very very large brain."

The statement comes as the US and China continue to engage in tit-for-tat tariffs that threaten to devolve into a fully-blown trade war.

Speaking on the tariffs, Trump said his Chinese counterpart Xi Jinping may not be his friend anymore, but did have new respect for him.

The Q and A came with plenty of funny voices, flamboyant gestures, and the president's favourite catchphrases as well.

A question about the laughter that followed Trump's General Assembly claim that his administration had “accomplished more than almost any administration in the history of our country" was immediately branded fake news.

"They weren't laughing at me, they were laughing with me, we had fun," Trump said.

Trump also defended his embattled pick for Supreme Court Justice, Brett Kavanaugh, who now faces accusations of sexual misconduct from three separate women.

"When I see it, I view it differently than somebody sitting at home watching television, where they say oh judge Kavanaugh this and that. It's happened to me many times, I've had many false charges."

Among the ramblings were also claims that ex-President Barack Obama came close to declaring war on North Korea.

The decorum of a presidential press conference seemed totally absent, as Trump mocked one reporter for appearing shocked when given a question, and repeatedly cut off a Kurdish reporter with assertions that the Kurds were "great people".

When one New York Times reporter asked a question, Trump repeated another of his catch phrases, calling it "the failing New York Times".

US Ambassador to the United Nations Nikki Haley also took it upon herself to back up the president's version of events at the UN, saying leaders weren’t laughing at Trump – they were respecting him and enjoying his honesty.

Haley went on Fox & Friends – a conservative daily morning show on which the president often appears– to say the coverage was unfair and blamed the media for the negative spin.

She said: “The media has got this so wrong. I deal with these leaders every single day, I know exactly how they think.

“Do they love America? No. Do they respect America? Now they do.”

She said the laughter was out of appreciation for the undiplomatic nature of his honesty.

“All day yesterday they were falling over themselves to get a picture with him, to talk about how great his speech was, how strong it was.”

She claimed UN leaders had “never seen anything like it”.

Trump is renounced for making outlandish and often demonstrably false statements during his presidency, beginning which claims such as his inauguration crowd being the largest in history, and that he won the popular vote.

Haley also touched upon claims Trump is not mentally up to the job – a claim that has been circulating for a while, but given new heat the New York Times reported deputy attorney general Rod Rosenstein suggested he should make covert audio recordings of Trump to build a case for removing him from office.

“It's gotten so disgusting, really.”

“The idea that he's not mentally fit, the idea that we would be talking about the 25th Amendment. None of that is true. It could not be farther from the truth.”

“How can you honestly think a man who doesn't know what he's doing is getting this much done on jobs, on trade deals … Americans are living better than they ever have and you're going to question his leadership.”

Bob Woodward's book, Fear: Trump in the White House, also said high ranking staff took it upon themselves to thwart the president's ideas out of fear he could hurt national security and international relationships.