Attempts to delegitimize Israel is a form of antisemitism, United Nations Secretary-General António Guterres said on Wednesday at a high level forum to combat hatred against Jews that was held on the sidelines of the General Assembly.

Modern antisemitism, the UN leader said, expressed “itself in attempts to delegitimize the right of Israel to exist, including calls for its destruction, using the pretext of the situation in the Middle East to target Jews and Jewish symbols.”

“The world is also seeing an alarming proliferation of neo-Nazi and white supremacy groups, and of those seeking religious and ethnic domination,” Guterres said at the event hosted by UNESCO. “This is tribalism run amok. Not only are their vile views coming into the mainstream, but the mainstream unfortunately, sometimes, is coming to them.”

Since taking office last year, UNESCO director-general Audrey Azoulay has highlighted the importance of combating antisemitism and Wednesday’s event was part of that effort.

Prime Minister Benjamin Netanyahu declined UNESCO’s invitation to attend the event, stating that the organization’s treat- ment of the State of Israel was tantamount to antisemitism.

A video of the event showed an empty chair next to a sign that read “Israel,” while foreign ministers and ambassadors from other countries sat in attendance and spoke out on the topic.

But at the UNESCO event, Guterres said the United Nations has a special obligation to fight antisemitism because the organization was created in the aftermath of World War II to help prevent tragedies such as the Holocaust.