Japan has a target under the Kyoto Protocol to cut its emissions by 6 percent from 1990 levels in the 2008-2012 period.

TEPCO said last week it would work existing thermal and nuclear plants harder to meet high summer electricity demand. The use of the thermal plants would raise carbon emissions.

"This (Kyoto target) will start from Aug. 1, 2008, so obviously it will have some impact if the restart is delayed," Economy, Trade and Industry Minister Akira Amari told a news conference.

The Nikkei newspaper reported last week that the government could order the company to keep the plant closed for more than a year while safety checks are carried out.

Japan's nuclear industry -- which supplies about one-third of the country's electricity needs and is central to its efforts to battle global warming -- has been tarnished by cover-ups of accidents and fudged safety records.

Amari said his ministry would seek help from other ministries to promote carbon-emissions reduction from households and various corporations so that the target could be achieved.

In May, Prime Minister Shinzo Abe proposed a global target to halve greenhouse gas emissions by 2050 and said Japan would support developing countries committed to halting global warming with a new form of financial aid.