United Nations, More than 165 UN member states are expected to attend a high-level signing ceremony for Paris climate agreement, including an estimated 60 heads of state and heads of government, a UN spokesman said here on Thursday. "This would set a record for countries signing an international agreement on a single day," Stephane Dujarric said at a daily news briefing here. UN Secretary-General Ban Ki-moon will host the signing ceremony for the Paris Agreement on Climate Change on Friday at United Nations Headquarters in New York, he said. "Thirteen countries have indicated that they will submit their instruments of ratification tomorrow," the spokesman said. "The full list is available online and that list will be updated." At 8.30 a.m. in the General Assembly Hall, the secretary-general will announce the start of the opening ceremony, and will address the event following remarks by a youth representative -- Getrude Clement, who is a 16-year-old radio reporter from Tanzania and youth representative and climate advocate with the UN Children's Fund (UNICEF), he said. "Children will be part of the event and there will be a performance by the Julliard brass quintet -- after this the secretary-general will declare the Paris Agreement officially open for signature, allowing Members States to take turns to sign the agreement," he said. "While the signing continues, those who have signed will head to the Economic and Social Council and Trusteeship Council Chambers to deliver their national remarks." The secretary-general is scheduled to hold a joint press conference with French President Francois Hollande before the high-level luncheon, the spokesman said, adding that there will also be a press conference by business and civil society representatives. The closing ceremony will start at around 6 p.m. featuring remarks by the secretary-general as well as the past, current and incoming Presidencies of the Conferences of Parties, he added.