US officials have claimed China is effectively locking out processed meat imports by erecting overly tough health rules on foreign meat and poultry products.

US diplomats told a meeting of the World Trade Organisation's (WTO) sanitary and phytosanitary committee such rules do not apply to Chinese-made meat and poultry products and also alleged "China's zero tolerance for pathogens on meat and poultry" is "not based on science".

China's stance could break its WTO commitments on fair and open trading, and could enable Washington to launch a formal disputes case to force Beijing to loosen its health rules. US officials have urged China to base its rules on objective risk assessments.