China has set a goal of further reducing the average PM2.5 density in the air－a bench mark to measure pollution－in 337 major cities over the next five years.

The target to reduce the average level of PM2.5 by 10 percent from the levels over the previous five years was announced on Feb 25 alongside a slew of other goals to tackle air pollution.

Over the next five years, major cities should also expand the proportion of days with good air quality to 87.5 percent annually, Liu Bingjiang, an official with the Ministry of Ecology and Environment, said at a news conference.

In the past five years, the country has focused on regulating sectors with heavy pollution, optimized the energy industry structure and vehicle use, launched campaigns to reduce seasonal pollution and identified more of its causes, Liu said.

China has achieved the goals outlined in its three-year action plan released in 2018. Last year, 337 major cities recorded good air quality for 87 percent of the year.

Last year, the number of cities that failed to meet the national standards for average PM2.5 density was 28.8 percent lower than in 2015, Liu said.

To further reduce air pollution, the ministry will prioritize cutting vehicle emissions for the next five years, Liu said, adding that lower carbon emissions and controlling air pollution had to be tackled simultaneously.