BEIJING, Jan. 14 (Xinhua) -- China will step up inspections of imported frozen products to prevent the spread of COVID-19 via cold chains, an official with the General Administration of Customs (GAC) said on Thursday.

Overseas food exporters should strictly follow the regulatory guidelines issued by the Food and Agriculture Organization of the United Nations and the World Health Organization to ensure their exports to China are not contaminated by the coronavirus during production, processing, storage or transportation, GAC spokesperson Li Kuiwen told a press conference.

So far, China has suspended imports from 124 cold-chain food manufacturers across 21 countries where employees had been infected with COVID-19. Among them, 107 companies voluntarily suspended exports to China following outbreaks, Li said.

China also strengthened its testing of imported cold-chain foods, particularly imported seafood, he said.

By Wednesday, approximately 1.3 million cold-chain products had been sampled for nucleic acid testing, with 47 tested positive, Li added.

China has adopted stricter cold chain requirements after it detected coronavirus on the packagings of various products.

As part of emergency preventive measures, the GAC suspends import declarations of foreign food makers whose products test positive for one to four weeks, the official said.

China also ramped up disinfection at ports to stem the spread of COVID-19 through imported cold chains. By Wednesday, the outer packagings of 13.17 million products had been disinfected at ports across the country.