US President Barack Obama has pressed China to recognise it is now a "grown up" economy and start behaving more responsibly on currency and trade issues hurting US companies.

China needs "to understand that their role is different now than it might have been 20 years ago or 30 years ago when if they were breaking some rules it didn't really matter, it didn't have a significant impact," Obama said at the conclusion of the Asia-Pacific economic summit (APEC) in Hawaii on Sunday.

Obama said that China must abide by international rules before it can become a partner in free trade.

He added that China had not done enough to re-value its currency and said Beijing's economic policies had disadvantaged the US.

'Level playing field'

Obama and Chinese President Hu Jintao had face-to-face talks during the meeting of leaders from a group of 21 countries that account for more than half of world economic output.

"There has been slight improvement over the last year partly because of US pressure but it hasn't been enough. It is time for them to go ahead and move towards a market based system for their currency," Obama said.

Al Jazeera's Patty Culhane, reporting from Honolulu, said Obama was "a little bit more blunt" when talking about China.

"Every step of the way [Obama was] trying to tie his business here [in the US] and overseas to creating jobs."

The US and China spar often on trade issues, with the US Senate recently passing legislation to encourage Beijing to let its currency, known as the yuan and the renminbi, rise more rapidly in value.

Obama added that he had consistently told Hu and other Chinese leaders that American companies were not afraid of competition, as long as there was a level playing field.