Washington, July 27 (DPA) Relations between the United States and China will be critical to success on a whole host of global issues, US President Barack Obama said Monday at the start of a two-day gathering of top officials from both countries.

'The relationship between the United States and China will shape the 21st century,' Obama said in Washington, urging progress on confronting the global economic crisis, climate change, nuclear proliferation and terrorism.

China's State Councillor Dai Bingguo said the interests of the US and China 'have never been interwoven so closely' and both countries would have to work together to help the global economy recover from a deep recession.

Obama said that bridging the divides between the two powers - the world's first and third-largest economies - was now often a 'prerequisite' for finding global agreements.