"De minimis imports, especially those from China, also circumvent most existing trade control mechanisms, including the Forced Labor Prevention Act and Section 301 tariffs used to hold trade fraudsters accountable," said a group of Democratic lawmakers.

A group of US House of Representatives members have called on President Joe Biden to close the 'de minimis' regulatory loophole that exempts imports under US$800 from paying tariffs, which currently benefits Chinese e-commerce companies such as Temu and Shein.

A total of 126 Democratic lawmakers have signed a joint letter to Biden urging him to use his executive powers to address the matter "urgently."

"Americans continue to die from mislabeled fentanyl pills ordered online, which evade inspection thanks to the 'de minimis' regime and end up right at citizens' doors," the document said.

"De minimis imports, especially from China, also circumvent most existing trade control mechanisms, including the Forced Labor Prevention Act and Section 301 tariffs used to hold trade fraudsters accountable," they added.

The signatories have said that up to 18 textile plants have closed in the United States in recent months due to the influx of cheap imports from China that have benefited from the 'de minimis' preferential regime.

The current exemption under the law was originally only applicable when the value of the products did not exceed 200 dollars (180.5 euros), but was revised to its current level in February 2016 by the Barack Obama administration to favour American e-commerce firms such as Amazon.

However, Shein and Temu have reportedly used this option to avoid the 25% increase in tariffs on goods from the Asian giant, which was decreed in 2018 by President Donald Trump.