Japan will tighten its criteria for supporting exports of coal-fired power plants amid criticism that the practice goes against global efforts to curb global warming.

"We've made big progress," Environment Minister Shinjiro Koizumi told reporters after a meeting of a government panel on infrastructure exports.

Japan has backed coal-fired power generation projects via such entities as the Japan Bank for International Cooperation and the Japan International Cooperation Agency.

The government's conventional stance is that if a foreign country has no choice but to turn to coal as its energy source, Tokyo will extend assistance for the installation of cutting-edge power generation facilities based on the country's request.

Energy-scarce Japan is the only nation among the Group of Seven countries pushing coal-fired power plants.

Faced with mounting global criticism, the government is taking a fresh look at its heavy dependence on coal-fired power generation, which is used to meet about a third of energy needs in Japan where most nuclear power plants remain offline after the 2011 crisis at the Fukushima No. 1 complex.

In recent years, Japan has been seeking to seize the opportunity to export quality infrastructure amid burgeoning demand in emerging nations in Asian and beyond, with a target of ¥30 trillion (about $280 billion) worth of orders in 2020.