China's environmental protection minister on Tuesday told a conference on controlling pollution in Songhua River that the river's water quality has improved significantly over the past five years.

Songhua River. [File photo]?

The extent of pollution in the Songhua River, which flows into a Sino-Russian border river, improved from "medium" to "light" between 2006 and 2010, Zhou Shengxian said at the event in Changchun, capital of northeast China's Jilin Province.

He said the country has targeted further improving the waterway's quality in the next five years, hoping to see the condition upgraded to "good," based on the Water Pollution Control Program on Key Rivers from 2011 to 2015 approved by the State Council, or China's Cabinet, in April.

Songhua River is the largest tributary of Heilong River, known in Russia as Amur River. The 1,900-km-long river originates in Jilin Province, traverses through Inner Mongolia Autonomous Region and Heilongjiang Province, and flows into Heilong River, which runs along the Sino-Russian border.

Rapid economic growth in Jilin, Heilongjiang and Inner Mongolia have posed challenges to pollution control work on the river, noted the environmental protection minister.

Zhou added that China will step up efforts over the coming five years by building more sewage treatment plants, protecting drinking water sources along the river and cutting industrial and agricultural pollution in the area.