The event, hosted every year by the synagogue’s Rabbi Arthur Schneier, a Holocaust survivor himself, took place in the presence of UN officials including Israel’s permanent representative Danny Danon as well as survivors of the Holocaust. “I will always be haunted by all that I saw and heard when I visited Auschwitz in 2013,” Ban told the congregation, “The testimonies of Holocaust survivors remind us what happens when we allow inhumanity to prevail. They also remind us of the power of the human spirit and the inherent dignity and worth of every person.”

The Secretary-General pointed out that the UN organized over 120 Holocaust remembrance events in 36 countries in the past year and works to educate about the tragedy through its Holocaust Outreach Program.

“We must work together to build bridges and end anti-Semitism, bigotry against Muslims, and all other forms of hatred,” he said. Ban also reiterated his words from the International Holocaust Remembrance Day ceremony which took place at the UN headquarters on January 27th and said that “those who deny [the Holocaust] only perpetuate falsehoods and make a mockery of the pain.”

In his address, the Secretary-General also mentioned past genocides in Rwanda, Bosnia Herzogovina and Cambodia and said he is “deeply disturbed” by the ongoing massacres in South Sudan, Syria, and by the killings inflicted by Daesh and Boko Haram.

“We must ask ourselves why and how this could happen and together work to prevent such atrocities from happening again,” he said. “I see international humanitarian law being flouted on a global scale. But I do not see the international community holding the perpetrators to account.”

Ban also stated that “demonizing and scapegoating people based on their religion, ethnicity or country of origin has no place in the 21st century.” The Secretary-General’s address came at the end of a week of sharp tension with Israel over his criticism that Jerusalem interpreted as giving a “tailwind” to terrorism.

The UN chief has infuriated Israel over the last 10-days, when he said that “as oppressed peoples have demonstrated throughout the ages, it is human nature to react to occupation, which often serves as a potent incubator of hate and extremism” and that it is “human nature” for Palestinians to react to the occupation.

After being sharply criticized by Prime Minister Benjamin Netanyahu, who said his words gave support for terrorism and were further proof that the UN has lost its moral standing, Ban – in an unprecedentedly sharp op-ed in The New York Times – charged, without mentioning Netanyahu by name, that he had twisted his words, and that Israel should not “shoot the messenger” and “lash out” at “every well-intentioned critic.”