Washington (CNN) President Donald Trump and first lady Melania Trump will travel to Pittsburgh on Tuesday, White House press secretary Sarah Sanders said Monday.

In an emotional announcement at the beginning of Monday's press briefing, Sanders called the "heinous killing" at the Tree of Life Synagogue in Pittsburgh "a chilling act of mass murder" and an "act of hatred," adding that anti-Semitism is a "plague to humanity" and something that all Americans "have a duty to confront."

The mass killing at a Pittsburgh synagogue was the deadliest anti-Semitic incident in US history. A heavily armed man burst in on a Jewish religious ceremony and killed 11 people before telling a law enforcement officer "I just want to kill Jews" after a week that was heavy with other acts of extremist violence motivated by politics.

"The American people reject hatred, bigotry, prejudice and violence," she said during the first White House press briefing in 26 days.

Sanders noted that the President -- whose daughter Ivanka, son-in-law Jared Kushner, and three grandchildren are Jewish -- "adores" and "cherishes" the Jewish community, her voice breaking at times.

"The President cherishes the American Jewish community for everything it stands for and contributes to our country. He adores Jewish Americans as part of his own family. The President is the grandfather of several Jewish grandchildren," she said, audibly beginning to cry. "His daughter is a Jewish American and his son-in-law is a descendant of Holocaust survivors."

Mixed welcome

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Sanders also said that the President wants to go to Pittsburgh to show support, adding that the Tree of Life rabbi "said that he is welcome" there, despite calls from a group of Pittsburgh Jewish leaders for him not to make the trip.

In an open letter to the President Sunday, the group told Trump that his words and policies over the past three years "have emboldened a growing white nationalist movement," and that he is not welcome until he "fully (denounces) white nationalism."

Tammy Hepps, a member of "Bend the Arc: Pittsburgh" who knew victims of Saturday's shooting, told CNN she wouldn't welcome Trump until he renounces "the words and the policies and the deeds that you have done that led to this day."

"The blood of these victims is on President Trump's hands," she told CNN. "That he has knowingly and intentionally and selfishly for years used this rhetoric to endanger our community and all the other communities that have been on the front line since he took office and even before that."

But Rabbi Jeffrey Myers, who was leading services at Tree of Life during Saturday's shooting, said that "the President of the United States is always welcome."

"I'm a citizen. He's my president. He is certainly welcome," he said.

On Monday, Sanders said that the Trumps would "express the support of the American people and grieve with the Pittsburgh community" during their trip.

Defense of rhetoric

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Sanders also defended Trump's rhetoric in the wake of the Pittsburgh attack and the bomb mailings last week.

"In moments when our country is hurting like we've seen in the last several days, to find ways to bring our country together and we've seen him do exactly that," she said. "However, the President is going to continue to draw contrasts, particularly as we go into the final days of the election, the differences between the two parties, particularly on policy differences, you'll continue to see him make those contrasts."

Sanders also offered a pointed critique to the media for suggesting Trump's rhetoric was part of what influenced the attackers.

"The very first thing he did was condemn the attacks, both in Pittsburgh and the pipe bombs. The very first thing the media did was blame the President and make him responsible for these ridiculous acts," she said. "That is outrageous, that that would be the very first reaction of so many people across this country. The only person responsible for carrying out either of these acts were the individuals who carried them out."