The mother of an American killed in last month's Libya consulate attack has said his death has been used by the Romney campaign for political purposes.
The Republican presidential nominee has been citing his meeting some years ago with former US Navy Seal Glen Doherty.
His campaign said the candidate would respect Barbara Doherty's wishes and stop mentioning her son.
The attack on the consulate in Benghazi on 11 September has become a political issue ahead of the election.
Doherty was killed in the attack in Benghazi along with Ambassador Christopher Stevens and two other officials.
"I don't trust Romney," Mrs Doherty told Boston news station WHDH.
"He shouldn't make my son's death part of his political agenda. It's wrong to use these brave young men, who wanted freedom for all, to degrade Obama," she said.
Campaigning on Tuesday in the state of Iowa, Mr Romney said that instead of running away from danger during the Benghazi consulate attack, Doherty had run towards it.
He reportedly used the anecdote as a metaphor for what Republicans must do to regain the White House in November's poll.
"They didn't hunker down where they were in safety," the former Massachusetts governor was quoted as saying by Reuters news agency.
"They rushed there to go help. This is the American way. We go where there's trouble."
"We go where we're needed. And right now we're needed. Right now the American people need us."
Mr Romney is reported to have mentioned Doherty at other events on Tuesday and Wednesday.
The Romney campaign said in a statement on Wednesday: "Governor Romney was inspired by the memory of meeting Glen Doherty and shared his story and that memory, but we respect the wishes of Mrs Doherty."
A campaign official confirmed Mr Romney would not re-tell the anecdote.
Friends of Doherty have spoken publicly about his encounter with Mr Romney at a Christmas party.
His friend, Elf Ellefsen, told a Seattle radio station: "He said it was very comical. Mitt Romney approached him ultimately four times, using this private gathering as a political venture to further his image.
"He kept introducing himself as Mitt Romney, a political figure. The same introduction, the same opening line. Glen believed it to be very insincere and stale," Mr Ellefsen added, according to ABC News.