Cameron said he wanted a "constructive" divorce from the EU on arrival in Brussels.
"Britain will be leaving the European Union but I want that process to be as constructive as possible and I hope the outcome can be as constructive as possible," Cameron said.
Economists at Bank of America Merrill Lynch (NYSE:BAC) believe the yuan could ease to 6.80 to the dollar, from around 6.65 now.
Fears of further yuan weakness could trigger more capital outflows, potentially tightening financial conditions in China and crimping economic growth, according to a BofA Merrill Lynch Global Research report this week.