The US is leading the call for the yuan to be more flexible

At present, the government in Beijing fixes the yuan against the US dollar.

The US, among other states, says the rate at which it is fixed is too low, giving Chinese companies unfair trading advantages.

But in Washington, Chinese officials rebuffed suggestions of an early shift to letting the financial markets set the rate.

"We have already said time and again we are moving toward a more market-based, supply-and-demand based, flexible exchange rate," the Chinese central bank's deputy governor, Li Ruogu, said.

"How long it takes, I don't know," he told a group of global bankers gathered for the annual meetings of the International Monetary Fund and World Bank.

"Because China has an 8,000 year history, a decade is truly a short period," he joked. "I've been asked numerous times, 'What is the time frame?' - I tell them, 'No time frame'."

The yuan is currently set at 8.28 to the dollar.

Banking reforms

The G7 group of nations has also been calling on China to adopt a more flexible currency system.

However, during their first ever get-together with G7 nations in Washington over the weekend, Chinese officials said they would not rush currency reforms.

In the past, the Chinese said changes will be difficult until the country puts in place a number of reforms to its banking system.

Some analysts believe such moves could take up to five years.

Meanwhile, Chinese officials said earlier actions, such as lowering credit, to slow growth in its economy were now paying dividends.

But the IMF - concerned that China's economy could overheat and generate inflation - said further measures to cool the economy would likely be needed.