Mayors from 18 cities of six countries, including Ulan Bator, Beijing, Guangzhou, Moscow, Ulan-Ude, Irkutsk, Seoul, Busan, Suwon and Tokyo as well as more than 300 representatives from international organizations are attending the two-day forum to discuss opportunities to cooperate and share experiences under a key topic "Improving air quality and reducing greenhouse gas emissions".

"Climate change is one of the inevitable and urgent global problems in the whole world. We are gathering here today to discuss ways to mitigate climate change impact, reduce greenhouse gas emissions at the city level and share experiences," Ulan Bator's mayor Sunduin Batbold said at the opening ceremony.

"Ulan Bator is severely affected by climate change. The frequency of drought and extreme wintry weather known as "dzud" has been increasing. Thousands of herders lose their animals almost to the dzud, which forces them to seek new opportunities in the capital city of Ulan Bator," the mayor said.

It has resulted in unplanned city expansion, and air and soil pollution, said Batbold.

He expressed the hope that the event will enhance partnership and cooperation of cities and introduce technologies to mitigate climate change impact, defining role and contribution of cities.

"Introducing selected technology that requires low expenses and shows result in a short time can be a good solution for development of a city," he added.

Ulan Bator initiated the Northeast Asian Mayors' Forum in 2014. Since then delegates from cities in the region gather every year to discuss environmental and socio-economic challenges and pressing issues.