The United Nations High Commissioner for Refugees said on Tuesday that “toxic" politics and media focused on refugees resulted in the terrorist attack on two mosques in New Zealand last month. Filippo Grandi told the UN Security Council that he has never seen “such poison” in politics, the media, social media and every day rhetoric about refugees, migrants and foreigners. “That should be a concern to us all,” Mr Grandi said. New Zealand witnessed the deadliest terror attack in the country’s history last month when 50 people were killed and another 50 injured in shootings at two mosques in Christchurch. An Australian white supremacist has been charged with the killings, which included many immigrants. The attacker live streamed footage of his rampage to Facebook, filmed with a head-mounted camera and posted a 70 page diatribe online in which he praised US President Donald Trump as a symbol of white identity. New Zealand prime minister Jacinda Ardern called the attack one of the country’s “darkest days”. Ms Ardern said the "world has been stuck in a vicious cycle of extremism which must end," and she will never utter the terrorist's name and "give his views the oxygen he wanted." Ms Ardern responsed to the attack by wearing a headscarf to meet the victim's families and urging to country to unite, a gesture which drew praise from Muslims worldwide. For his part, Mr Grandi described the response by the people and leadership of New Zealand as "exemplary". He said the attacks showed that governments needs to address the issue of language on social media and politics. "It has become a factor of security and stability for all countries," Mr Grandi said. If the issue is left "unchecked it may have very grave consequences, not only for our work but for the world in general,” he said. The UN official urged governments to "respond to these toxic trends in a firm and organised manner, restate the values that underpin the solidarity that we must provide to refugees and reaffirm... that our societies will not be really prosperous stable and peaceful if they do not include all." In a heartfelt speech, Mr Grandi said he had worked with refugees for over three decades and has seen "much solidarity, even heroism in some of the responses that are provided on the ground" to help them. And "that solidarity is still very strong" in many parts of the world, "from African villages to the border between Bangladesh and Myanmar, to communities in Latin American helping Venezuelans," he said. If conflicts were prevented or resolved, most refugee flows would disappear, he said. “The 70 million figure of refugees and displaced, would not exist if an end would be put to the conflicts that cause most of this displacement.”