China has pledged that there will be an adequate supply of coal throughout the Spring Festival holiday season, after four top coal producers recently struggled to keep up with demand and raised prices, according to the nation's top economic regulator.

The National Development and Reform Commission, which is also known as the NDRC, said on Sunday that coal supplies have been increased in February and that demand for coal to generate electricity has reduced because the weather has warmed up.

"China's coal-fired electricity has been and will be guaranteed," said Meng Wei, a spokesperson at the NDRC.

Meng said daily production of coal between Feb 1 and Feb 8 reached 6.32 million metric tons, up 7 percent on the volume produced in late January.

Daily consumption, fell by 5 percent, to 6.15 million tons compared with late January.

Meng said coal production in Shanxi province and Shaanxi province in January increased by more than 30 and 50 percent, respectively, compared to last year.

Earlier this year, China's four major coal producers struggled to keep up when snowstorms swept across Central and Eastern China.

The four, China Huaneng Group, China Datang Corp, China Huadian Corp, and State Power Investment Corp, said in a joint report at the time that there was potential for a shortage of coal and interruption of electricity supplies.

To address the challenge, the NDRC limited the selling price of coal to 750 yuan ($119) per ton and ordered increased production, as well as smoother coal transportation.

Going forward, China National Coal Group said it will work with railway administrations in order to increase coal transportation through northern ports, including Qinhuangdao.

In order to ensure supply, holidays for staff at major coal mines and power stations could be shortened to one or two days from the original seven days enjoyed by most workers at Spring Festival.

Major power generation groups, including Shenhua Group, will continue to work during the festival in order to guarantee supply.