The declaration, seen by Reuters, may be an effort by China to reduce the additional testing it has carried out on imported foods over the last week and make exporters responsible for guaranteeing their products’ safety, one meat importer who had signed it said.

He declined to be identified because of the sensitivity of the issue.

The French pork industry association Inaporc also received the notice, an official said.

China’s General Administration of Customs did not immediately respond to a fax seeking comment.

The declaration says the exporter is willing to comply with Chinese laws and guidance from the U.N. Food and Agriculture Organization and the World Health Organization to ensure food imported into China is not contaminated with the virus that causes COVID-19.

“In the event that a new case/suspected case of COVID-19 is detected in a food enterprise, or if there is a risk of contamination of food products exported to China, we are willing to take all necessary measures to eliminate food safety risks and protect consumer health,” it adds.

Beijing began testing imported food for the coronavirus after an outbreak in a wholesale food market last week.

In Tianjin, the primary port for Beijing, authorities are testing all containers of meat, importers said.

More than 30,000 samples of meat, seafood, vegetables and fruit were tested between June 11-17. All tested negative for the coronavirus, customs said on Thursday.

“It’s very costly and time-consuming to test all products. They’re asking suppliers to sign this letter so they can go back to normal,” said the meat exporter.

How much weight the declaration will carry, however, is unclear.

“If any shipments are found to have COVID-19, they will be destroyed anyway, with or without the letter,” said another meat supplier who had not signed it.