Agence France-Presse: The United States and China on Saturday put differences over human rights aside and pledged here Saturday to work more closely in tackling the global economic crisis and climate change. Giving hope for a new era of co-operation between the world powers, visiting Secretary of State Hillary Clinton and Chinese Foreign Minister Yang Jiechi said they will plan for the Group of 20 (G-20) summit in London on April 2. “As we start the new administration of President (Barack) Obama, we …