Mr Geithner will testify in front of two congressional hearings later The US has filed two new cases against China at the World Trade Organization (WTO), claiming that Beijing has been breaching global trade rules.
The move comes at a time of rising tensions between Beijing and Washington, notably over the level of the Chinese currency, the yuan.
US Treasury Secretary Timothy Geithner is to testify at two congressional hearings on the yuan later.
In prepared comments, he expressed concern about the slowness of change.
“We are concerned, as are many of China’s trading partners, that the pace of appreciation has been too slow and the extent of appreciation too limited,” he said.
But a spokeswoman for the Chinese Foreign Ministry said: “The appreciation of the renminbi [yuan] can’t solve the trade deficit with China.
“Pressure cannot solve the issue. Rather, it may lead to the contrary.”
China has been accused by the US and others of holding the value of the yuan down, making its exports artificially cheap.
However, in recent months Beijing has taken steps to make its currency more flexible by raising the centre point of the currency’s official trading band.
BBC World Service’s business reporter Theo Leggett says that while trade tensions between Washington and Beijing are not new, they have been escalating in recent weeks, amid complaints from US politicians that China is keeping its currency artificially low against the dollar.
The Obama administration has indicated that it plans to take a tougher stance with China on trade issues, including demanding that Beijing move more quickly to reform its currency system.
The two cases the US has brought at the WTO are a sign of that new approach.
The first case concerns duties imposed by China on imports of specialist steel used in the power generation industry.
China says they were introduced to prevent subsidised shipments from driving local producers out of business, but the US trade representative Ron Kirk has accused Beijing of protectionism.
The second complaint concerns the market for electronic payment systems in China, which is dominated by a single domestic firm, China Union Pay.
The US says its providers are being excluded from the bulk of this market.
This article is from the BBC News website. © British Broadcasting Corporation, The BBC is not responsible for the content of external internet sites.