A coal-fired power plant in Nantong, Jiangsu province. According to a midterm assessment in 2013, the nation fell behind in some of its pollution targets over the past three years.

Economic and environmental officials vowed on Monday to step up efforts in the next two years to ensure China's energy and environment goals for 2015 are within reach, despite efforts in the 2011-2013 period that failed to measure up.

Experts said fulfillment of the nation's energy saving and emissions reduction targets would also lay a foundation for meeting the country's goal of slashing pollution and improving air quality by the end of 2017.

China is facing "a tough situation" in hitting its energy and emissions targets for 2015, and wide-ranging efforts must be put in place within the next two years, said Xu Shaoshi, chairman of the National Development and Reform Commission, on a national teleconference in Beijing on Monday.

According to a midterm assessment in 2013, the nation fell behind in some of its pollution targets over the past three years. For instance, the target for nitrogen oxide reduction between 2011 and 2013 was 60 percent, but only 20 percent was accomplished during that period.

The numbers indicated that significant ground must be covered over the next two years, said Li Junfeng, director general of National Center of Climate Change Strategy Research.

"If the nation fails to realize its energy saving and emissions reduction targets for 2015, it would be even harder for it to hit the 2017 target for improving air quality and cutting emissions," said Li. China aims to reduce the level of airborne particulate matter by at least 10 percent in major cities between 2013 and 2017.

According to a two-year action plan released by the State Council, China's cabinet, on Monday, the country aimed to cut carbon intensity (carbon emissions per unit of GDP) by 4 percent in 2014 and 3.5 percent in 2015. China's carbon intensity should fall by 17 percent, according to its 12th Five-Year Plan (2011-2015).

China also aims to reduce energy consumption per unit of growth by 3.9 percent this year and next in order to meet its 16 percent goal for the 2011-2015 period.

Half of the country faced an alarming rate in the first quarter in terms of energy consumption growth, according to Xu. The country has allocated provincial targets for annual energy consumption growth for 2014 and 2015. More than 10 provinces' targets exceed 10 million tons of standard coal.

"The target remains too lax; some provinces could contribute more. However, some local officials still hold the old way of thinking that economic development remains top priority, and they haven't paid enough attention to environmental issues," Li said.

Local officials will face greater accountability for their performance in saving energy and cutting emissions to ensure realizing the nation's energy intensity and emissions targets, said Xu of the NDRC.

At the same time, more stringent requirements have been imposed on newly built projects. Zhou Shengxian, China's environmental protection minister, said the ministry will further strengthen environmental impact assessment and total emissions will be regarded as a precondition in assessing projects.

Also, China plans to take more than 5 million "yellow label" vehicles that fail to meet fuel standards off its roads this year in a bid to improve air quality.