A senior US trade official has warned that China could face punitive "trade measures" if it does not adequately open up its market to American firms.
Chinese exports to the US have reached record levels
Deputy US Trade Representative Karan Bhatia told the BBC that China was failing to treat US companies fairly.
The growing US trade gap with China has fuelled calls for the US to toughen its stance over Beijing's trade practices.
China has responded by warning that trade sanctions imposed by the US against it would damage both countries.
Level playing field
Mr Bhatia told the BBC's The World This Weekend programme that China had "benefited enormously" from gaining access to US markets.
But Beijing was not doing enough to ensure an open and level playing field for US companies in China, Mr Bhatia said.
The US, he said, was "perfectly prepared" to use trade measures to force the Chinese government to grant US firms greater access to China's domestic market.
The US trade deficit with China jumped by 24.5% to a record $201.6bn in 2005, according to figures published earlier this month.
However, Mr Bhatia stopped short of suggesting that Washington would move directly to restrict Chinese companies from accessing its market.
"We are not going to resort to protectionism. The answer is not going to be to shut down US markets or to build up walls around our borders," he said.
US Trade Representative Rob Portman said last week that the US was readjusting its view towards the Asian economic powerhouse.
He announced the setting up of a task force to ensure that China complies with the rules of global trade.
Critics in the US argue that the country is being flooded with cheap Chinese exports, leaving domestic rivals struggling and threatening jobs in America's industrial heartlands.
But China has warned the US against introducing trade measures against it, and called on Washington to resolve its differences over trade "on the basis of equality".
"Imposing pressure or sanctions to solve problems between the two will not be beneficial for China-US trade relations and will not be beneficial for the United States' interests," Chinese foreign ministry spokesman Qin Gang said.