More than 44,000 people have signed an open letter from progressive Jewish leaders saying President Trump is not welcome in Pittsburgh until he denounces white nationalism.

Eleven members of the Pittsburgh affiliate of Bend the Arc: A Jewish Partnership for Justice penned a letter to Trump following Saturday’s shooting at the Tree of Life synagogue that left 11 congregants dead.

“President Trump, you are not welcome in Pittsburgh until you stop targeting and endangering all minorities,” the letter reads. “President Trump, you are not welcome in Pittsburgh until you cease your assault on immigrants and refugees.”

White House press secretary Sarah Huckabee Sanders on Monday announced that Trump and the first lady on Tuesday will travel to Pennsylvania to meet with victims’ families “to express the support of the American people.”

The president and the White House have condemned the attack as anti-Semitic, but critics have said the condolences are not enough. Democrats and progressive activists have blamed the president’s aggressive rhetoric.

Before the massacre, the alleged shooter posted on social media about the so-called caravan of Central American migrants slowly making their way to the U.S. border. Trump on Monday referred to the caravan as an “invasion.”

Republicans and others have said the only person at fault is the gunman.