China has reacted angrily to a US ban on seafood products, after American authorities claimed they included antibiotics banned in the US.
The ban includes catfish, prawns and eels
The head of China's health inspection watchdog, Li Changjian, called the ban indiscriminate and unacceptable.
The US Food and Drug Administration (FDA) said on Thursday it would stop shipments of catfish, basa, shrimp, dace and eel.
It is the latest in a number of US warnings about Chinese products.
Mr Li urged the US to "properly deal with the problem as soon as possible".
He had a phone conversation with US Health Secretary Mike Leavitt, urging the US to deal with the issue.
The FDA said it had found that Chinese seafood tested between October 2006 and May 2007 was repeatedly contaminated with antimicrobial agents.
Some of the substances included nitrofuran, malachite green and fluoroquinolone, which, according to the FDA, may help build up a resistance to antibiotics when used in food animals.
The ban is not imposed on food which has already been imported into the US, only future shipments.
In what is thought to be a response to the US move, Chinese authorities this week seized two shipments of American food, saying they were substandard.