China's efforts to fight desertification in northern China have made major strides over the past 45 years but challenges remain, Yue Taiqing, deputy head of the Forestry Bureau of Three-North, said at a news conference on Monday.

The Three-North Shelter Forest Program, launched in 1978, will plant trees across 13 provinces in northern China by 2050, according to the National Forestry and Grassland Administration.

So far, the program has planted and conserved 32 million hectares of forests and restored 85 million hectares of degraded grassland, Yue said.

Forest coverage in the project area has increased from 5.05 percent in 1978 to 13.84 percent.

"The project has established a green Great Wall to act as a shield against sandstorms, protect soil and water and promote agricultural and pastoral development in the northern border of China," Yue said.

Yue said challenges remain in sand control and desertification prevention.

"Despite achievements in the program, the work remains challenging due to wide distribution and severe condition of desert land. The environmental fragility of the region and persistent environmental issues make the task even harder," he said.

The program's region holds 84 percent of the desert land and 73 percent of the soil erosion area in China.