SEOUL: US President Barack Obama and China's President Hu Jintao pledged to work together Thursday, 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-on-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. However, the two sides have been at loggerheads over a broad range of issues for months, especially economic, and Obama's reinvigoration of US engagement in China's backyard in Asia may also strain ties. 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 600 billion dollars 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. With those disputes in mind, Obama said Thursday the US-China relationship was stronger and broader than it had been in the past, because their talks now ranged over global issues as well as bilateral ones. “As two leading nuclear powers obviously we have (a) special obligation to deal with nuclear proliferation,” Obama said at the meeting in a Seoul hotel. Obama, who earlier called on North Korea to show a “seriousness of purpose” before six-nation talks on its nuclear program can resume, told Hu it was important to press on Pyongyang the need to avoid “provocative” acts.