US President Barack Obama and China's President Hu Jintao today pledged to work together, following a rocky period of trade and currency spats coupled with diplomatic shadow-boxing in Asia.The leaders, meeting in Seoul, put on a public show of comity in their seventh one-one-one talks since Obama took office, in an encounter expected to smooth the way for Hu's state visit to Washington in January.US officials said the 80-minute meeting was dominated by divisions over exchange rate policy and the need to improve the atmosphere of the broader US-China relationship ahead of Hu's visit.Obama said that it was “wonderful” to see Hu again, and argued that as leading economic and nuclear powers, both nations had an obligation to work together to halt proliferation and to ensure strong, balanced growth.Hu said in a brief photo-op ahead of the talks on the sidelines of a G20 summit that China was ready to work with Washington to “increase dialogue, exchanges and cooperation,” and said he hoped his US visit would be a success.Washington has become increasingly impatient with China's so-far limited efforts to allow the value of its yuan currency to rise. US officials say the unit's value is kept artificially low to boost Chinese exports.Beijing meanwhile has been leading global criticism at the US Federal Reserve's plan to pump USD 600 billion into the US economy, arguing Washington is risking the global recovery in its own search for growth.China suggested that the G20 should monitor policy shifts by the US central bank and was also furious at Obama's decision to praise the Nobel committee for awarding its annual peace prize to dissident Liu Xiaobo.