U.S. President Barack Obama has invited the leaders of 16 major economies to Washington for a forum on energy and climate next month, the White House announced Saturday. Obama, who recently turned his attention to the need for more clean-energy funding, has also asked U.N. Secretary-General Ban Ki-moon to attend. The forum, scheduled for April 27-28, seeks to "generate the political leadership necessary" for a successful outcome at the U.N. climate change negotiation to be held in Copenhagen, Denmark, in December, the White House said in a statement. Aside from the United States, the 16 other major economies are Australia, Brazil, Canada, China, the European Union, France, Germany, India, Indonesia, Italy, Japan, Korea, Mexico, Russia, South Africa and the United Kingdom.