Bend the Arc, a Pittsburgh-based Jewish group, wrote an open letter to Trump declaring that he is not welcome in the city unless he denounces white nationalism.
"For the past three years your words and your policies have emboldened a growing white nationalist movement. You yourself called the murderer evil, but yesterday’s violence is the direct culmination of your influence," members of Bend The Arc wrote in a letter to Trump. "President Trump, you are not welcome in Pittsburgh until you stop targeting and endangering all minorities."
Over 21,000 people have signed the online petition.
Trump said on Sunday that he would be travelling to Pittsburgh without offering specifics, according to the Pittsburgh Post-Gazette.
In Sunday's interview, Peduto pointed out that Trump might not even make it in time for the funerals, as Jewish ritual proscribes burial 24 hours after death, if possible.
"This is a Conservative synagogue," Peduto said. "So the funerals will be very quickly. As soon as tomorrow. So that's really up to the families and whether they would want the president to be here.
Peduto emphasized the need to join together and support the families of the victims, throughout the interview.
"In Pittsburgh our hearts are broken...we understand that an attack against our Jewish community is an attack against our entire city. We're here right now to help the victims' families," Peduto said.