Simon Stiell, the UN climate change executive secretary, said in a message on the official conference app that he wanted to draw attention to the organisation’s code of conduct at gatherings.
“Harassment-free sessions can be achieved only if all of us act consciously and create a safe space where this doesn’t happen,” he said.
“There is a process for investigating reported cases, and consequences when reported cases are found to have substance.”
It was unclear whether Mr Stiell’s message was in response to a specific complaint made at the conference or a routine reminder about the UN’s code of conduct.
The Independent has contacted the UN for comment.
UN conferences, meetings and events should be “professional, respectful, inclusive and create harassment-free environments for all participants”, the organisation’s code of conduct says.
Harassment in any form, including sexual harassment, will not be tolerated, it adds.
This year’s conference, being held in Sharm El-Sheikh, started on 6 November and will run until Friday, with world leaders trying to build on the commitments set out in the 2015 Paris climate accord to limit global warming to 1.5C (2.7 Fahrenheit) by the end of the century if possible.
But scientists say that with about 1.2C of warming already reached, that target is likely to be missed.
Speaking on Tuesday, Ugandan climate activist Vanessa Nakate slammed world leaders who persist in backing new fossil fuel projects despite scientists’ warnings that this will push temperatures across the planet to dangerous highs.
“The focus for many leaders is about making deals for fossil fuel lobbyists, surviving the next election cycle and grabbing as much short-term profit as possible,” Ms Nakate said at an event on the sidelines of the summit.