President Barack Obama and China's President Hu Jintao have agreed to forge "more positive" ties between their giant nations in their first telephone call since the US leader came to power, a White House spokesman said. White House spokesman Robert Gibbs said that Obama and Hu spoke Friday morning US time of their "intention to build a more positive and constructive US-China relationship." Meanwhile, Beijing said Saturday that the Chinese leader urged better ties with the United States in his first phone conversation with Obama, and called for both sides to resist trade protectionism.