Muhammad Ali family lawyer to Trump: Thanks, but no pardon needed

US President Donald Trump's comment on Friday that he might pardon boxing legend Muhammad Ali drew a prompt response from the late heavyweight champion's estate: thanks but no thanks.

"We appreciate President Trump's sentiment, but a pardon is unnecessary. The US Supreme Court overturned the conviction of Muhammad Ali in a unanimous decision in 1971. There is no conviction from which a pardon is needed," said Ron Tweel, a lawyer for the boxer's estate and his widow, Lonnie.

Before leaving to attend the Group of Seven summit in Canada, Trump told reporters he was considering pardoning some 3,000 people, including Ali, who died in 2016.

"I'm thinking about somebody that you all know very well, and he went through a lot and he wasn't very popular then," Trump said.

"His memory is very popular now. I'm thinking about Muhammad Ali. I'm thinking about that very seriously."

The boxer refused to be inducted into the US Army in 1967 during the Vietnam War, claiming conscientious objector status, and was sentenced to five years in prison. He was never imprisoned while his case was under appeal and in 1971 the US Supreme Court overturned the conviction.

Tweel, reached by telephone at his home in Virginia, said the White House had not contacted him or Lonnie Ali about a potential pardon. He said he had been in contact with the widow after Trump's comments and they decided to issue a statement on behalf of the family.

"We heard what he was contemplating and it needed a response," he said.

It was unclear why Trump would consider a pardon, given that Ali's conviction was overturned. The White House did not immediately comment on the lawyer's statement.

Trump said many of the 3,000 people he was considering for pardons were treated unfairly or given unfairly long sentences.