Washington (CNN) President Donald Trump said Friday he is considering posthumously pardoning boxer Muhammad Ali, who was convicted in 1967 after refusing military service in Vietnam -- even though Ali's attorney called it "unnecessary."

"I'm thinking about Muhammad Ali. I'm thinking about that very seriously and some others," Trump said, while speaking to reporters at the White House before departing for the Group of Seven summit. "And some folks that have sentences that aren't fair."

Ali's attorney, Ron Tweel, told CNN that there was no contact whatsoever between anyone in the Trump administration and members of the Ali family about the issue.

"So, it's not like for weeks or days the administration has reached out to the Ali family. None of that," he told CNN. "This was all spontaneous and I think, as a lot of people like to say, impulsive."

Tweel said he could only guess what spurred the President's comments.

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