U.S. President Donald Trump on Sunday vowed to fight anti-Semitism, in a prerecorded video speech to the World Jewish Congress Plenary Assembly in New York City.

In the speech, given on the eve of Holocaust Remembrance Day (Yom Hashoah), Trump praised Israel as a “great nation”.

“On Yom Hashoah, we look back at the darkest chapter of human history. “We mourn, we remember, we pray, and we pledge: Never again. I say it, never again,” Trump said, according to the JTA news agency.

“The mind cannot fathom the pain, the horror, and the loss,” he continued. “Six million Jews, two-thirds of the Jews in Europe, murdered by the Nazi genocide. They were murdered by an evil that words cannot describe, and that the human heart cannot bear.”

“Today, only decades removed from the Holocaust, we see a great nation risen from the desert and we see a proud Star of David waving above the State of Israel,” Trump added. “That star is a symbol of Jewish perseverance. It’s a monument to unyielding strength. We recall the famous words attributed to Theodor Herzl: If you will, it is no dream. If you will it, it is no dream.”

Trump also promised to combat anti-Semitism and bigotry, while also making a veiled reference to Iran, whose leaders have repeatedly called for Israel’s destruction.

“We must stamp out prejudice and anti-Semitism everywhere it is found,” said Trump. “We must defeat terrorism, and we must not ignore the threats of a regime that talks openly of Israel’s destruction. We cannot let that ever even be thought of. To all of you tonight, who have come from around the world, let it be known, America stands strong with the State of Israel.”