UN Secretary-General Ban Ki-moon responded harshly on Friday to a comment made by Turkish Prime Minister Recep Tayyip Erdogan in his presence, calling Zionism a crime against humanity.

Erdogan told the UN Alliance of Civilizations meeting in Vienna on Wednesday, “Just as with Zionism, anti-Semitism and fascism, it has become necessary to view Islamophobia as a crime against humanity.” The event was devoted to promoting dialogue between Islam and the West.

In a statement issued by Ki-moon’s spokesperson, the UN chief conveyed his criticism: “The secretary-general believes is it is unfortunate that such hurtful and divisive comments were uttered at a meeting being held under the theme of responsible leadership.”

The Turkish prime minister’s comment immediately drew harsh criticism from UN Watch, a Geneva-based watchdog group monitoring anti-Israel bias and human rights abuses at the organization.

“Erdogan’s misuse of this global podium to incite hatred, and his resort to Ahmadinejad-style pronouncements appealing to the lowest common denominator in the Muslim world, will only strengthen the belief that his government is hewing to a confrontational stance, and fundamentally unwilling to end its four-year-old feud with Israel,” UN Watch said in a statement.

The group also criticized the UN chief — “who was present on the stage yet stayed silent” — for not immediately condemning Erdogan’s remarks.

“We remind Secretary-General Ban Ki-moon that his predecessor Kofi Annan recognized that the UN’s 1975 Zionism-is-racism resolution was an expression of anti-Semitism, and he welcomed its repeal,” the statement said.

UN General Assembly Resolution 3379, which was adopted by a vote of 72 to 35 (with 32 abstentions), stated that “Zionism is a form of racism and racial discrimination.” Due to US pressure, it was revoked in 1991.

Israel and Turkey enjoyed close diplomatic and business relations for years until a gradual deterioration accelerated due to the May 2010 Gaza flotilla incident, in which clashes between pro-Palestinian activists and IDF troops aboard the Mavi Marmara ship resulted in the deaths of nine Turkish citizens and injuries to several Israeli soldiers.

Relations between Ankara and Jerusalem have since remained sour, with Turkey demanding an apology, and compensation for the families of those killed, as prerequisites for the warming of ties.