"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."

Over 165 countries expected to attend signing ceremony for Paris climate agreement

At 8:30 a.m. EDT (1330 GMT) 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. EDT (2100 GMT) featuring remarks by the secretary-general as well as the past, current and incoming Presidencies of the Conferences of Parties, he added.