The 13th session of the Conference of the Parties (COP13) to the United Nations Convention to Combat Desertification (UNCCD) opens in Ordos city in North China's Inner Mongolia autonomous region on Sept 11, 2017. [Photo/Xinhua]

China will stick to its commitment to fight against desertification and further strengthen the cooperation with all parties and international communities to make joint efforts for a better world, President Xi Jinping said in a congratulatory letter to a UN environment meeting on Monday.

The high-level segment of the 13th Session of the Conference of the Parties to the Convention to Combat Desertification is being held in Ordos, Inner Mongolia autonomous region, from Monday to Wednesday.

"Desertification is a challenge that is faced by all people, which also has a major influence on world development. We need to promote the principle of respecting and protecting nature. The environment should always be our priority," Xi wrote in the letter.

Xi said it has been 21 years since the UN desertification convention took effect. Major efforts from the parties have produced significant changes since then, but many people still suffer from desertification.

"The theme of this year's conference is Combating Desertification for Human Well-being. Under new frameworks, some major positive influence will be seen to build a better ecosystem for the whole world," he said.

Vice-Premier Wang Yang, who attended the conference, said China will fulfill its commitment and achieve its sustainable development goals by 2030, with green building a crucial part of the country's effort to combat desertification.

About 400 million people in 18 Chinese provinces were affected by desertification in the 1950s, according to the State Forestry Administration. A mass campaign against desertification started in 1956.

In 1978, the Chinese government decided to launch several mass campaigns to combat desertification, such as the Three-North Shelter Forest Program placing forest windbreaks in 13 provinces in northern China and known as the "Great Green Wall".

"China is very experienced in land renewal. We've seen a successful case in the Kubuqi Desert, where 6,000 square kilometers of land once covered by sand is now green and more than 100,000 of its people are now out of poverty," said Monique Barbut, the UN desertification convention executive secretary.

China joined the UN convention in 1994 and promulgated the world's first law dedicated to sand prevention and control in 2001. Most nations use regulations for this purpose.

In the past five years, the area of desert decreased in China by 242,400 hectares. In 12 northern provinces and regions including Inner Mongolia, the number of people living under the poverty line fell from 47.11 million to 13.42 million.

Liu Dongsheng, deputy director of the State Forestry Administration, said China has set a goal to turn half of the country's desert into green areas by 2020. And by 2050, he said all the country's desert that can be changed will be made green.