President Trump on Tuesday paid tribute to Holocaust victims and survivors with a resolute speech in which he vowed that his administration would confront anti-Semitism and protect Israel from those seeking the Jewish state's destruction.

“Those who deny the Holocaust are accomplices to this horrible evil,” Trump said in a 15-minute address before a crowd of several hundred, including some survivors, at the U.S. Holocaust Memorial Museum's Days of Remembrance event at the U.S. Capitol. “We will never be silent . . . in the face of evil again.”

Trump's remarks came in the wake of stumbles by his campaign and the White House that have led to criticism that the president and his aides have minimized the Nazi genocide of the Jewish people during World War II. This month, White House press secretary Sean Spicer appeared to suggest that Syrian President Bashar al-Assad had committed more egregious attacks on his people than did Adolf Hitler, who oversaw the extermination of more than 6 million Jews in Europe.

“This is my pledge to you: We will confront anti-Semitism,” Trump said, receiving applause from the audience. “We will stamp out prejudice, we will condemn hatred, we will bear witness and we will act. As president of the United States, I will always stand with the Jewish people, and I will always stand with our great friend and partner, the state of Israel.”

Trump spoke extensively about what he called the “Nazi genocide” and paid tribute to “those who survived history's darkest hour.”

“You saw the organized attempt at the extermination of an entire people — a great people, I must say,” he said. “You survived the ghettos, the concentration camps and the death camps, and you persevered to tell the stories.”

Vice President Pence, senior White House adviser Jared Kushner, Treasury Secretary Steven Mnuchin and National Economic Council Director Gary Cohn were among the guests sitting in the front row. Kushner, the president's son-in-law, has acted as Trump's top adviser on Israel, helping write his first speech on Israel during the campaign.

Before Trump spoke, Ron Dermer, Israel's ambassador to the United States, said the Holocaust “laid bare unimaginable hatred” and was defined by “horrors” and “cruelty.”

Dermer praised the U.S. missile strike on a Syrian airfield that Trump authorized in retaliation for Assad’s chemical weapons attack in that country's civil war.

“That decision was a defiance of indifference,” Dermer said. “And if evil triumphs when good men do nothing, we should all seek to live in a world that defies indifference.”

Dermer went on to say that the civilized world should be “prepared to use military might to confront barbarism.”

Trump returned the praise, saying of Dermer that “he’s done a great job and said some wonderful words.”

Trump said millions of “innocent people were imprisoned and executed by the Nazis without mercy — without even a sign of mercy. Yet even today, there are those who want to forget the past, and there are even those filled with such hate — total hate — that they want to erase the Holocaust from history. Those who deny the Holocaust are an accomplice to this horrible evil and we will never be silent. We just won’t. We will never, ever be silent in the face of evil again.”

The president spoke at length about the legacy of Elie Wiesel, the Holocaust survivor and political activist who died last summer, noting that Tuesday marked the first Day of Remembrance since his death.

“His absence leaves an empty space in our hearts, but his spirit fills this room,” Trump said. He said that Wiesel had a “gentle spirit,” that he “lived through hell” and that his “courage still lights the path from darkness.”

Trump and several people close to him have previously faced accusations of anti-Semitism and making insensitive remarks regarding the Holocaust. During the campaign, Trump tweeted a graphic attacking Hillary Clinton that was circulating online in anti-Semitic circles. It featured a Star of David on top of piles of money. Although the image was deleted, Trump later said he wished that his staffers had left it in place and allowed him to defend it.

After the election, the Anti-Defamation League’s chief executive opposed Trump’s selection of Stephen K. Bannon as his chief strategist because Bannon once led the Breitbart news site, which the organization considers “the premier website of the alt-right, a loose-knit group of white nationalists and unabashed anti-Semites and racists.”

In January, the White House released a statement on International Holocaust Remembrance Day, which marks the anniversary of the liberation of the Auschwitz concentration camp, that made no mention of Jews or the anti-Semitic views that fueled the Holocaust. At the time, White House spokeswoman Hope Hicks said the omission was intentional because the White House staff is an “incredibly inclusive group, and we took into account all of those who suffered.”

When confronting accusations of anti-Semitism, Trump and those close to him note that his daughter Ivanka, son-in-law and three grandchildren are Jewish. Ivanka Trump posted a family photo Monday on social media that appears to have been taken at the White House and includes the message: “During #Passover, we are called upon to reflect on the significance of the exodus from Egypt and celebrate the great freedoms we enjoy today! #ChagPesach.”

At the conclusion of his speech Tuesday, Trump declared: “We must never, ever shrink away from telling the truth about evil in our time. Evil is always seeking to wage war about the innocent and to destroy all that is good and beautiful about our common humanity, but evil can only thrive in darkness.”