Guterres met with worshippers at the Islamic Cultural Center's mosque in Manhattan as they gathered ahead of Friday prayers and offered "solidarity with the Muslim community from NY to New Zealand and beyond".
New Zealand came together in a national day of reflection Friday to mark a week a week since a white supremacist gunned down 50 people at two mosques in Christchurch.
"I made a decision to fly to Christchurch this week because I feel it is my obligation as a Muslim to support those who are facing catastrophe and adversity", he wrote for News Corp.
Prime Minister Jacinda Ardern led an estimated 5,000 people standing quietly at Hagley Park in front of the Al Noor mosque, where most of the victims died.
Broadcasting the Friday Prayers Azan live and commencing the parliamentary process with recitation from the Holy Quran and her address with the Islamic salutation have gone a long way in alleviating the pain of the relatives and dependents of the victims of the bloodbath. "Their blood has watered the seeds of hope", he said in prayers broadcast nationally.
Police will return the al Noor and Linwood mosques to leaders on Saturday after crime scene investigators finished their work and contractors donated their time to return them to their original condition.
They took their cue from a movement within the country to honor the 50 persons killed in the mosque shootings March 15 by wearing hijabs, beginning with Auckland doctor Thaya Ashman.
Turkey's Erdogan to NZ terrorist: You will pay for this
Peters said he had complained directly to visiting Turkish Vice-President Fuat Oktay and Foreign Minister Mevlut Cavusoglu.
Australian boxer Anthony Mundine, centre, joins Muslims for the call to pray at Hagley Park, opposite the Al Noor Mosque.
Ms Ardern has encouraged as many New Zealanders as possible to use the day to pause and reflect. "We are determined to not let anyone divide us", he added, as the crowd erupted with applause.
The OIC meeting in Istanbul was also attended by Erdogan, who briefly met Peters on the sidelines.
"We are broken-hearted, but we are not broken", he said.
"Every semi-automatic weapon used in the terrorist attack on Friday will be banned", Ardern said. "Retweeting or sharing screenshots of this type of content only serves to spread it further and gives it more visibility to more people".
"I'm feeling like if I died and my father and brother is still alive, it will be better", he said, wiping tears from his eyes.
"We are so happy that this prayer will be broadcast to the entire world so that everyone can be part of it", Mustafa Farouk, president of the Federation of Islamic Associations of New Zealand, said in a statement announcing the prayer session.