US Secretary of State Condoleezza Rice has urged China to open its economy further and explain the build-up of its military. On a three-day official visit to Australia, Rice questioned the reasoning behind double-digit increases in defense spending. She also touched on intellectual property rights, the fixed yuan and state ownership of large parts of the economy. ï¿½The growth of the Chinese economy, if done in a rules-based way in which China is fully obeying the rules of the global economy, is a positive development for international growth and for the US,ï¿½ said Rice. Foreign Ministry spokesman Qin Gang defended the transparency of rises in military spending. ï¿½China is a responsible country devoted to world peace and stability and the promotion of common development,ï¿½ said Qin.