Poland should rethink its dependence on heavily polluting coal and focus instead on developing cleaner energy sources, the International Energy Agency said Wednesday.

"The new energy strategy must determine if coal is going to sustain the Polish economy over the longer term or if it is to be a burden for the country," the IEA said in its 2016 review of the country's energy sector.

The agency reported that coal accounted for 81 percent of Poland's electricity generation in 2015 and that the heavily indebted coal-mining sector -- one of Europe's largest -- provided more than 100,000 politically sensitive jobs.

The right-wing government of Beata Szydlo plans to present a revised energy strategy this year, but the coal-miner's-daughter-turned-prime minister has long insisted that plentiful domestic coal is key to Poland's energy security.

Her Law and Justice (PiS) administration has also set tough regulations on the installation of wind turbines, in effect blocking competition from the renewables sector, which in 2014 covered about 10 percent of national energy needs.

The IEA said "the future of renewable energy in Poland looks uncertain" in light of this and other legislative moves by the PiS.

The agency commended the government's efforts to replace antiquated coal-fired electricity and heating plants with more efficient and cleaner units.

But it cautioned that significant policy support was needed to reach Warsaw's "very ambitious goal" of having one million electric vehicles on the roads by 2025.

Poland's energy strategy "will require significant investments to reduce the share of carbon-intensive power plants and increase the share of low-carbon energy, including nuclear energy and renewables", IEA director Fatih Birol said in Warsaw.

The agency also noted that "air pollution is one of the largest environmental health risks" facing Poles.

A study last year by the European Environmental Agency blamed air pollution -- caused in large part by the burning of coal -- for an estimated 50,000 premature deaths a year in the country of 38 million people.

Poland plans to ban the use of low-quality coal -- an important but costly measure in a country where coal is used to heat 72 percent of single family dwellings.

Lawmakers in the Krakow region of Poland, considered the area with the dirtiest air in the country, also on Monday approved an anti-smog plan that calls for replacing the most polluting heating stoves by 2023.