China urged some individuals in the United States to immediately stop making unjustified accusations against its products and slandering China, and called on them to do something useful to help the US to better respond to the COVID-19 pandemic, the Ministry of Commerce said.

The ministry made the remark after White House trade adviser Peter Navarro accused China on Monday of shipping "low-quality and even counterfeit" novel coronavirus antibody testing kits to the US and of "profiteering" from the outbreak.

Navarro's accusations are groundless and extremely irresponsible, the ministry's spokesperson said in a statement released late on Tuesday.

Since the outbreak of the global epidemic, China has maintained close communication and cooperation with the certification and registration agencies of various countries, including the US Food and Drug Administration, to ensure China's exports of anti-epidemic materials meet the quality requirements of importers, the spokesperson said.

China has exported tens of millions of novel coronavirus antibody testing kits, the spokesperson said, adding that the products have been widely praised by the international community. China has not yet received any feedback from US purchasers and users regarding the quality of testing kits.

The Ministry of Commerce stressed it takes joint efforts to fight COVID-19, as it is still spreading throughout the world and has become a common enemy of mankind.

China urged certain parties in the US to take action more conducive to cooperation between the two countries in fighting the epidemic, according to the statement.

Barbara Woodward, British ambassador to China, said she was pleased by China's help in shipping over 21 million pieces of protective equipment and more than 1,000 ventilators to the United Kingdom from April 2 to 25.

"I am delighted that we have been able to deliver huge quantities of lifesaving equipment for the National Health Service and our social care services," she said. "Our strong trade relationship with Chinese partners has meant that we have been able to source the right equipment, and we have seen both UK and Chinese firms contribute to our joint fight against COVID-19."

The UK government chartered 20 flights from British Airways and Virgin Atlantic as well as various air cargo operators to ship the goods from China to Britain.

By Saturday, Chinese companies had exported epidemic prevention and control goods to 191 countries and regions this year. It has received encouraging feedback about its medical supplies from countries, including France, Denmark and Algeria, over the past two months, the Ministry of Commerce said.

To protect the international image of products made in China, the government has tightened procedures required to ship medical supplies abroad and advised foreign importers and users to closely follow the specifications for proper use of the supplies, said Jin Hai, head of the General Administration of Customs' department of general operations.

Starting on Sunday, manufacturers exporting products verified or registered overseas－including COVID-19 test kits, medical masks, medical protective suits, ventilators and infrared thermometers－had to provide an export declaration of medical supplies to Customs authorities, who then could clear the products in accordance with the business lists.

To defend its reputation, Chinese medical device maker Guangzhou Wondfo Biotech Co issued a statement on Tuesday to clarify that its antibody testing kits exported overseas to detect SARS-CoV-2－the virus that causes COVID-19－met the quality requirements of China's National Medical Products Administration and countries to which they were exported.

The statement was released in reply to the Indian Council of Medical Research's suggestion that Indian states stop using the rapid antibody testing kits produced by Wondfo and Zhuhai-based Livzon Pharmaceutical Group Inc, following complaints that they are not fully effective. The product had been validated and approved by the council through India's National Institute of Virology.

Ji Rong, a spokeswoman for the Chinese embassy in India, rebutted such claims on Tuesday, saying it is irresponsible and unfair to label Chinese products as 'faulty' and to look at issues with prejudice, the embassy said on its website.

She said there are strict requirements for transportation, storage and use of the kits. Any step or usage not carried out by trained personnel in accordance with product instructions will result in testing accuracy variations.