US President Donald Trump knew it was wrong to order election-eve hush money paid to two women who claimed to have had affairs with him, according to his former lawyer.

Michael Cohen made the comments in an interview on US television.

Mr Trump acted because he "was very concerned about how this would affect the election," Cohen told ABC News of the women's allegations, in his first comments since being sentenced to three years in prison earlier this week.

Mr Trump has said he never directed Cohen - who is due to surrender to custody by 6 March - to break the law.

But Cohen, asked if Mr Trump knew the payments to Stormy Daniels and Karen McDougal were wrong, said "of course".

Cohen challenged Mr Trump's assertion that he never told him to break the law.

"I don't think there is anybody that believes that," Cohen told George Stephanopoulos on "Good Morning America".

ABC released excerpts of the interview.

"First of all, nothing at the Trump Organization was ever done unless it was run through Mr Trump. He directed me to make the payments, he directed me to become involved in these matters," Cohen said.

"He knows the truth. I know the truth. Others know the truth," he added.

"And here is the truth: People of the United States of America, people of the world, don't believe what he is saying. The man doesn't tell the truth. And it is sad that I should take responsibility for his dirty deeds," said Cohen.

Asked if he believed Mr Trump was telling the truth about Russia's meddling in the US election, Cohen said "no" but he declined to comment further.

"That sort of gets into the whole investigation right now between (the) special counsel's office, the attorney general's office, you also have the Southern District of New York - I don't want to jeopardise any of their investigations," he said.

In a separate development, The New York Times and Wall Street Journal reported that federal prosecutors have opened another line of election-related inquiry, investigating whether foreigners illegally funneled donations to Mr Trump's inaugural committee and a pro-Trump super PAC.

The Times cited people familiar with the inquiry as saying it focused on whether people from Qatar, Saudi Arabia and the United Arab Emirates used straw donors to make donations in hopes of buying influence over US policy.

Mr Trump denies having affairs with the women who were paid off just weeks before the election in which he beat Hillary Clinton.

The US President enters his third year in office facing an increasingly perilous situation as federal prosecutors and the special investigation into alleged collusion with Russia close in on him and his inner circle.

But he was as combative as ever on Twitter yesterday when he sought to distance himself from Cohen, his loyal fixer for a decade.