In tones that were at times defiant, China pressed the United States to act promptly and fairly and cautioned that Chinese seafood products should not be “automatically held and rejected indiscriminately.”
In a statement issued late Friday, China’s top quality watchdog, the General Administration of Quality Supervision, Inspection and Quarantine, acknowledged that there were safety problems with Chinese seafood exports but also said that it had found similar problems in food imported from the United States.
“Just like the U.S. imported food in China, there are quality problems with aquatic products that are exported to the U.S. by some Chinese enterprises,” the government said in a statement posted on one of its Web sites. “China has cooperated and handled these problems properly.”
The statement came after the Food and Drug Administration in the United States said Thursday that it would effectively block the sale of five types of farmed fish, including shrimp and catfish, unless independent testing proved that the goods were free of contamination.
China’s sharp response to the restrictions in the United States sets the stage for what could be a high-stakes trade dispute over seafood, one of the fastest-growing segments of the global food market.
F.D.A. officials declined to comment on China’s response.
China is already the world’s biggest producer and exporter of seafood, and a growing portion of that is sent to the United States, which imports more than 80 percent of its seafood.
But China also has leverage because it is one of the largest importers of American grain, and its food market is increasingly enticing to big American corporations. Indeed, United States authorities are pressing China to lift a ban on American beef.
“If I were the Chinese I would not start a trade war over this,” said Dermot Hayes, a professor of agricultural economics at Iowa State University. “They have a huge trade surplus with us, so it’d be like picking a fight with a rich grandmother. This is a problem that can easily be solved by scientists.”
China has an increasingly poor track record of exporting tainted seafood products to the United States. Time and again over the last few years, Chinese seafood has tested positive for carcinogens and excessive antibiotic residues.
Chinese goods make up about 22 percent of United States seafood imports. But they accounted for about 63 percent of the shipments that were refused by the F.D.A. last year for having animal drug residues.
And early this year, the F.D.A. said it saw a spike in rejections of Chinese seafood products, particularly catfish, shrimp, eel, basa (which is related to catfish) and dace (which is like carp). Those five farm-fished products are facing new F.D.A. restrictions.
Growing concerns about tainted seafood have come after a string of recalls involving Chinese products as varied as pet food, toothpaste, toys and tires.
The recalls have alarmed members of Congress and American consumers and created an ugly side show to already tense trade relations between China and the United States.
China has insisted that its food is largely safe. But regulators here have also vowed to overhaul the country’s food safety regulations and to step up inspections of exports. But American regulators have grown impatient.
To combat the safety problems involving imported Chinese seafood, the F.D.A. said Thursday that it planned to hold all shipments of the restricted seafood products unless they are proven to be safe. Until now, the F.D.A. has only done spot checks on those and other products, testing only a tiny fraction of food imports from China.
In its statement Friday, China said it was willing to cooperate with United States regulators and even proposed its own system of testing and certifying the quality of certain food exports.
Chinese regulators also said that they were “highly concerned” about food safety matters and were working to fix the problem involving tainted seafood exports.
But in striking back at American regulators, China insisted that food products made in the United States also had quality and safety problems. For instance, earlier this week, China rejected batches of orange pulp and apricots from the United Sates, contending that they contained mold, excessive amounts of bacteria and other contaminants.
Andrew Kaelin, managing director of AIS Aqua Foods, a seafood importer, said he thought that Chinese regulations were generally effective but were simply not enough to control the huge number of aquaculture producers. Consequently, he said, it was up to importers and processors to make sure the shipments were clean.
“We test all our shipments before they leave,” he said, explaining that his company ships primarily Chinese scallops, calamari and tilapia to the United States. He said that Chinese regulators stopped a shipment of his that contained shrimp on Friday until he could provide the testing paperwork.
Stacey Viera, a spokeswoman for the National Fisheries Institute, which represents the American seafood industry, said that she expected the restricted Chinese seafood would continue to be sold in the United States. She said, however, that there might be a delay while importers set up testing procedures for the seafood, which may create a temporary problem for restaurants and stores.