US President Donald Trump offered a whirlwind of commentary about world events, admitted to knowing about a payment to porn actress Stormy Daniels and praised rapper Kanye West in a wide-ranging phone interview on the Fox and Friends program.

Key points: Trump says lawyer Michael Cohen did "absolutely nothing wrong"

Trump says lawyer Michael Cohen did "absolutely nothing wrong" President calls Russia investigation a "disgrace"

President calls Russia investigation a "disgrace" Praised rapper Kanye West's 'good taste'

Mr Trump admitted his personal lawyer Michael Cohen represented him "with this crazy Stormy Daniels deal", after previously denying any knowledge of a payment Mr Cohen made to the porn actress.

Mr Trump told reporters weeks ago that he had no knowledge of a $US130,000 ($172,000) payment Mr Cohen made to Ms Daniels before the 2016 election in exchange for her silence about an alleged sexual encounter with Mr Trump in 2006.

Arguing that Mr Cohen was one of his "many attorneys", Mr Trump told Fox and Friends: "He represents me like with this crazy Stormy Daniels deal.

"From what I see, he did absolutely nothing wrong. There were no campaign funds going in."

Mr Trump called Mr Cohen a "good guy" but said he handled only "a tiny, tiny little fraction" of his overall legal work.

Mr Cohen is facing a federal criminal investigation into his personal business dealings.

Ms Daniels' lawyer Michael Avenatti responded on Thursday: "Mr Trump and Mr Cohen previously represented to the American people that Mr Cohen acted on his own and Mr Trump knew nothing about the agreement with my client, the $130k payment, etc.

"As I predicted, that has now been shown to be completely false."

Stormy Daniels says she had a sexual encounter with Donald Trump in 2006. (AP: Matt Sayles)

Trump 'won't be involved' in special counsel's Russia probe

Mr Trump also told the show that he "won't be involved" in the special counsel investigation into Russian election meddling, but added he may change his mind.

The President said special counsel Robert Mueller's probe was a "disgrace" and criticised federal agents for exercising search warrants on Mr Cohen and former campaign chairman Paul Manafort.

"I am very disappointed in my Justice Department," he said.

"But because of the fact that it's going on, and I think you'll understand this, I have decided that I won't be involved.

"I may change my mind at some point, because what's going on is a disgrace."

Mr Trump's comments come as the Senate Judiciary Committee is poised to vote on a bill to protect Mr Mueller's job.

Mr Trump again branded the Russia probe a "witch hunt" and repeated that there was "no collusion" between his campaign and Russia.

Kanye has "good taste"

Donald Trump said he and Kanye knew each other a "little bit", with the pair having met at Trump Tower in December 2016. (AP: Seth Wenig)

Mr Trump also touched on his recent Twitter exchanges with rapper Kanye West, praising him for having "good taste" for supporting him.

Mr Trump said he knew the rapper "a little bit" and always got along with him, and said West has noticed the low unemployment rate for black Americans.

"He sees that stuff and he's smart and he says, 'You know what, Trump is doing a much better job than the Democrats did,'" he said.

The President also addressed the withdrawal of his pick to lead Veterans Affairs, Ronny Jackson, after allegations about misconduct mounted and a Senate panel postponed his confirmation hearing.

"He would have done a great job," Mr Trump said of Dr Jackson, who had no experience running a large organisation.

"These are all false accusations. They're trying to destroy a man."

Trump said he has a new candidate with "political capabilities" for the job.

Dr Jackson said he was withdrawing from consideration after allegations that the White House doctor had been lax with prescription drugs and drank alcohol on the job.

"While I will forever be grateful for the trust and confidence President Trump has placed in me by giving me this opportunity, I am regretfully withdrawing my nomination to be Secretary for the Department of Veterans Affairs," Dr Jackson said in a statement.

Ronny Jackson has withdrawn from consideration to head up Veterans Affairs. (AP: Alex Brandon)

AP/Reuters