The start of a process by the United States to withdraw from the 2015 Paris climate accord is "very disappointing," Japan's environment minister said Tuesday.

"Creating a decarbonized society is a pressing issue and (the U.S. move) is very disappointing," Environment Minister Shinjiro Koizumi told reporters.

"It'd be impossible to urge President (Donald) Trump to reverse the decision," Koizumi said.

Chief Cabinet Secretary Yoshihide Suga also expressed disappointment over the U.S. exit, saying the international community as a whole needs to tackle global warming.

[Getty/Kyodo]

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U.S. starts process to withdraw from Paris climate accord next year

"In view of the G-20 Osaka summit declaration, we will explore ways to cooperate with the United States to address the issue of climate change," the top government spokesman said at a press conference.

The United States, the second-largest carbon dioxide emitter, said Monday it has formally notified the United Nations of its withdrawal, initiating a year-long process to pull out of the landmark pact intended to fight global warming.

Trump announced his decision in December 2017 to exit the pact adopted at a U.N. conference on climate change in Paris, saying that it is unfair to his country.

In June, leaders from the Group of 20 economies gathering in Japan's Osaka left a rift over climate change, with the United States reiterating its intention to leave the Paris accord while the other members pledged to work toward its full implementation.

The Paris Agreement, the successor to the 1997 Kyoto Protocol, aims to keep rising global temperatures to "well below" 2 C higher than preindustrial levels, so as to limit the occurrence of droughts, floods, melting glaciers, rising sea levels and other results of global warming.