United Nations – Introducing a new "Action Plan" to combat hate speech, U.N. Secretary General Antonio Guterres warned Tuesday that the world is in danger of forgetting the lessons of the Holocaust. And he blamed the leaders of certain democracies as well as dictatorships for fueling the spread of hate speech around the world.

"In both liberal democracies and authoritarian regimes, some political leaders are bringing the hate-fueled ideas and language of these groups into the mainstream, normalizing them, coarsening the public discourse and weakening the social fabric," Guterres said.

Asked by CBS News to specify which countries' leaders he was referring to, he replied, "Some political leaders are, to a certain extent, mainstreaming what has been until now particularly the expression of extremist groups." Pressed on which ones, he would only say with a smile, "We have seen it in some recent electoral campaigns."

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Asked about it again during his press availability, Guterres said it was a "strategy" not to call any country out by name. Rather, he said he wanted to keep the focus on the substance of the issue.

U.N. Secretary General Antonio Guterres Reuters

"My objective today is not to name or shame any individual because unfortunately we are dealing with something that has spread … and we are facing a massive phenomenon."

The focus of the event, which also featured Under Secretary General Adama Dieng, special envoy for the prevention of genocide, was the resurgence of and spread of hate speech today.

The U.N. chief said that while hate speech has been around for a long time, it is now amplified by social media. He lamented what he called a "groundswell" of "xenophobia, racism and intolerance, violent misogyny, and also anti-Semitism and anti-Muslim hatred" in countries around the world.

"When the [U.N.] Charter was drafted," Guterres said, "the world had just witnessed genocide on an industrial scale. Hate speech had sown the seeds, building on millennia of scapegoating and discrimination against the Jews, and culminating in the Holocaust."

"Seventy-five years on," he said, "we are in danger of forgetting this lesson."

Over the years, he said, "hate speech has been a precursor to atrocity crimes, including genocide, from Rwanda to Bosnia to Cambodia."

Fighting hate speech at the U.N. and online

Dieng said the U.N.'s Action Plan aims to tackle hate speech from its root causes to its impact, and to develop "counter-narratives." He said the plan "never calls for restrictions of freedom of expression and opinion to address hate speech."

The European Union's U.N. Ambassador João Vale de Almeida told diplomats gathered: "Hate speech is spreading in all our societies and constitutes a threat to open, pluralist and democratic societies."

He said the E.U. has enacted legislation to protect victims of crime and has a range of policy actions, including a "Code of Conduct" on countering illegal hate speech online, devised together with Facebook, Microsoft, Google (which owns YouTube), and Twitter, put into place in May 2016.

Some U.S. lawmakers believe that the U.S. is lagging behind, struggling with the debate over free speech, while countries like New Zealand and Great Britain are responding to extremist propaganda and misinformation online by imposing stricter regulations on big tech companies.

At the U.N. on Tuesday, Courtney Nemroff, the Trump administration's deputy U.S. representative to the Economic and Social Council of the U.N., said, "The United States strongly agrees that the Plan of Action should not endorse limitations on freedom of speech, and that more speech, not less, is needed," adding that in the U.S. "our experience has taught us that speech restrictions do not work."

Nemroff also said, "Our strong belief in freedom of expression does not mean that we sit idly by as individuals and groups seek to spread toxic expressions of hatred," and added that all individuals should speak out against hate speech.

In March, less than two weeks after a white supremacist live-streamed his deadly attack on worshipers at two New Zealand mosques, Facebook announced that it was broadening its definition of banned hate speech and taking action against white nationalism and white separatism.

But many critics have faulted big tech companies for not acting more aggressively to curtail the spread of extremist content on their platforms.

The U.N. Action Plan

U.N. Secretary General Guterres said the Action Plan aims to:

Enhance efforts to address the root causes of hate speech, "recommending a coordinated response, including efforts to identify those who engage in hate speech, and those who are best placed to challenge it" through education as a "preventive tool;" and

Enable the United Nations to respond effectively to the impact of hate speech on societies.

The U.N. chief was clear on the goal, if not precisely how it would be executed. "Hate speech is in itself an attack on tolerance, inclusion, diversity and the very essence of our human rights norms and principles," and "undermines social cohesion, erodes shared values, and can lay the foundation for violence," Guterres said.