Christiana Figueres, executive secretary of the U.N. Framework Convention on Climate Change, has urged Japan to set an ambitious goal of emission cuts from 2020 and contribute over $1 billion to a new fund for combating global warming.

"My expectation of Japanese contributions is the same as my expectation from every other country," Figueres said in an interview on Saturday.

Parties to the convention are required to announce their reduction targets by the end of March. Prime Minister Shinzo Abe's government on Friday began discussions on the matter.