The Gold Star father also suggested someone should read the late Arizona senator's book to Trump.
Khan said "the same hate" that sparked the New Zealand shooting also prompted the Charleston and Pittsburgh shootings.
“We should embrace one another, we should move forward, we should not try to re-create the 1940s, 1930s,” the Gold Star father says.
"This office has not dignified him ― he has in fact undignified the office.”
The Gold Star parents weigh in on the president's controversial comments about consoling the families of fallen service members.
The father of a slain Iraq War veteran gave a stirring speech against Trump at last year's Democratic convention.
They say Tom Perriello will resist President Donald Trump.
The Gold Star father is "disheartened" by the GOP response but still has hope.
And they seem to have found their strongest argument against it.
“We will not be withdrawing. We will not be pushed back," the Gold Star father said.
He isn't committed to "pursuing justice for all Americans," Khan said.
He said he was absolutely sure he did the right thing in speaking out against Trump during the election.