NEW YORK, Jan. 20 (Xinhua) -- UN Secretary-General Antonio Guterres on Saturday warned against all forms of hate at a ceremony marking the International Day of Commemoration in Memory of the Victims of the Holocaust.

In his remarks delivered at Park East Synagogue in New York, the UN chief said that "as I scan the global landscape today, I am sorry to say that the state of our world is messy. And the state of hate is high."

"Neo-Nazi threat is growing," he noted.

"Almost 80 years after the fall of the Nazi regime, its symbols, mindsets and language are very much with us," said Guterres.

"Some still seek to deny or diminish the fact of the Holocaust. Others downplay the complicity of their citizens and former political leaders," he said.

"And we see example after example of the rise of the neo-Nazi threat," he warned.

Guterres said that "all of us today have a special obligation. An obligation to never lose sight of what went wrong and how it happened."

He also called upon the international community to "be ever vigilant in the face of persistent anti-Semitism and other forms of hate in our time."

Guterres told the gathering that anti-hate organizations are now tracking hundreds of pro-Nazi and other such groups.

"With just a little research, we were able to quickly identify 65 groups in 25 countries. These are located not just in Europe and North America but in every region of the world," he said.

Their followers, and the "likes" they receive on social media, number in the tens of thousands, he said.

"Sixty thousand people marched recently in one country in support of the continent's far right movements, with placards reading 'White Europe' and 'Clean Blood,'" he continued.

According to the UN chief, the neo-Nazi group called "Combat 18" has re-emerged, including through a concert in a European country attended by thousands. "A recent far right march, called 'Revolt Against the Traitors' by the participants, sought to march near a synagogue on Yom Kippur, the holiest day on the Jewish calendar."

"Last year, hundreds of neo-Nazis gathered to mark the 30th anniversary of the death of Rudolf Hess, one of Hitler's leading associates," he warned.

"A prominent nationalist in one European country described a Holocaust memorial as a 'monument of shame' and pledged to 'rewrite the history books' of the Nazi era," the Secretary-General warned.

On the internet, the white nationalist online ecosystem is "phenomenally larger" than any other extremist groups, said Guterres.

"This year marks the 80th anniversary of Kristallnacht, the night of broken glass, on which so many Jewish synagogues, shops and other centers of life were destroyed," he said.

The UN chief said that on this day, "two fundamental duties" should be born in mind: to remember the utter evil and systematic attempt to eliminate the Jewish people and to be ever watchful of dark clouds on the horizon.

Citing former Chief Rabbi of the United Kingdom Lord Jonathan Sacks as saying that "the hate that begins with Jews never ends with Jews," the UN chief said "we must stand together against the normalization of hate."

"We must stand up to political opportunists who profit by scapegoating and vilification," he said, adding that "we must reject those who fail to understand that as societies become multi-ethnic, multi-religious and multi-cultural, diversity must be seen as a source of richness and not a threat."

The theme of this year's Holocaust Remembrance Day is "Need for Education and Leadership," which Guterres said highlights "the importance of education as a shared responsibility."

The United Nations and the Holocaust Outreach Program will continue to do its part, he noted.

"Leaders across the board must step up," he said.

"It matters what leaders say. It matters what kind of example is set by public officials from mayors to ministers to heads of state. We must never be bystanders when lives and values are at stake."

"Let us work together to build a world of pluralism, mutual respect and coexistence for all," the secretary-general concluded.