Japan should set an ambitious target for curbing greenhouse gas emissions, Environment Minister Tetsuo Saito told Prime Minister Taro Aso on Tuesday.

"Though 100 percent of what I have said will not be reflected in his decision, I believe my feelings were communicated to the prime minister," Saito said after meeting with Aso, who plans to reveal the emissions target Wednesday.

The government is expected to set the figure for 2020 at a 7 percent decrease from 1990 levels, or a 14 percent decline from 2005 levels. Saito has asserted that Japan should aim for a 15 percent to 25 percent cut from 1990 levels or a 21 percent to 30 percent reduction from 2005 levels.