China's environment is in a critical condition, especially water and air quality, vice minister of environmental protection Li Ganjie said Wednesday.

At a press conference ahead of World Environment Day on Thursday, Li said that although China's environment has improved in general, water quality is "not optimistic" and air quality in cities is "serious".

In China's top 10 river basins in 2013, about 9 percent of the water was class V; the worst level. Compared to 2012, the percentage of class V water quality dropped by only 1.2 percentage points. Of 4,778 monitoring sites for groundwater almost 60 percent were poor or extremely poor.

Water quality offshore is not good either, said Li, with 18.6 percent of offshore water areas only reaching class IV. Water quality in the East China Sea and in four of China's nine biggest bays was extremely poor.

As for air quality in cities, only three of the 74 monitored cities met the national standard for good air in 2013.

Soil pollution and land degradation are also serious, according to Li, who added that agricultural acreage reduced by 80,200 hectares in 2013, and a total of 295 million hectares, or 30.7 percent of China's land area, are suffering soil erosion.