BONN - As sexual harassment scandals rock the worlds of entertainment, business and politics, a "handful" of complaints have cropped at UN climate talks in Germany, an official said.

"There have, to my knowledge, been a handful of complaints here in Bonn," Nick Nuttall, a spokesman for the UN climate secretariat, said in response to an AFP query.

He gave no details about the nature of the claims and did not name the alleged perpetrators.

"My understanding is that the people concerned, after raising the issue to the UN and other relevant authorities, did not wish to proceed to any further formal process."

For the first time in more than two decades of UN climate conferences, the secretariat has informed delegates of a "zero tolerance" approach to sexual harassment, adding a notice to the daily agenda.

The November 6-17 Conference of Parties to the UNFCCC climate convention is the 23rd such annual meeting - which gives it the acronym COP 23.

"The UNFCCC secretariat and COP 23 organisers have a zero tolerance for any form of harassment, including sexual harassment, and will deal with such complaints promptly," the notice states.

It encouraged "reporting of any incident" to the UN security services, and provided two telephone numbers.

In recent weeks, a flood of sexual harassment claims have led to complaints, and in some cases charges, against public figures including Hollywood producer Harvey Weinstein, actor Kevin Spacey, comedian Louis C.K. and senior politicians.

US President Donald Trump, criticised for boasting about groping women, has himself been accused of sexual misconduct more than a dozen times, but rejects the claims.

UN climate chief Patricia Espinosa said last week the secretariat did not have enough money for a "dedicated team" on sexual harassment, adding: "We need a lot of support."

She said she did not know of any specific complaints among the secretariat team.

"As you know there are many situations where people... don't come forward formally. Sometimes... women speak about certain situations but then from there to really going into a formal process of making an accusation, it takes a lot of courage."

Climate negotiator Nazhat Shameem Khan of Fiji, which presides over the current round of negotiations, welcomed the UNFCCC's "zero tolerance" stance.

"The difficulty is people don't come forward they don't complain and one of the reasons that they don't is that there are no frameworks in place to deal with it," she said.