BEIJING—Chinese President Hu Jintao emphasized the need for cooperation with the U.S. in areas from new energy to space ahead of his visit to Washington this week, but he called the present U.S. dollar-dominated currency system a "product of the past" and highlighted moves to turn the yuan into a global currency.

"We both stand to gain from a sound China-U.S. relationship, and lose from confrontation," Mr. Hu said in written answers to questions from The Wall Street Journal...